semi-annual progress report

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SEMI-ANNUAL PROGRESS REPORT FORMER CHEVRON FACILITY NO. 122208 5801 RIGGS ROAD, CHILLUM, MARYLAND

JULY THROUGH DECEMBER 2009

1.0 INTRODUCTION Pursuant to the U.S. Environmental Protection Agency (EPA) Administrative Order, Docket Number RCRA-03-2008-0355TH (AO), Chevron U.S.A. Inc. (Chevron) is conducting work at and adjacent to the former Chevron Service Station (Facility No. 122208) located at 5801 Riggs Road, Chillum, Maryland (the site). In accordance with Section VI, Paragraph E, subsection 3(c). of the AO, Chevron has prepared this Semi-Annual Progress Report (Report) to describe actions taken by Chevron pursuant to the AO. The reporting period for this report is July 2009 through December 2009. The remainder of the Report is divided into the following seven sections and five appendices:

• Section 2.0 - Work Conducted During the Reporting Period • Section 3.0 - Summary of Findings • Section 4.0 - Permit Compliance • Section 5.0 - Summary of Deviations from Approved Plans, Problems Encountered, and

Corrective Actions Taken • Section 6.0 - Summary of Meetings with Public and Government • Section 7.0 - Changes in Key Personnel During the Reporting Period • Section 8.0 - Projected Work for the Next Reporting Period • Tables

o Table 1: Comparison of Detection Results for Sampling Methods o Table 2: Summary of Groundwater and Soil Vapor Monitoring Program

• Figures o Figure 1: Cumulative Total Hydrocarbons Recovered and Groundwater Treated Since

1990 o Figures 2-7: Groundwater Contour and Iso-Concentration Maps o Figures 8-25: Benzene and MTBE Trend Analyses

• Appendix A - Dual-Phase Extraction System-Groundwater Extraction Data o Figure: Process and Instrumentation Diagram o Table A-1: Total Fluids Extraction System Data o Table A-2: Total Fluids Extraction System Influent Analytical Results o Table A-3: Total Fluids Extraction System Effluent Analytical Results

• Appendix B - Dual-Phase Extraction System-Soil Vapor Extraction Data o Figure: Process and Instrumentation Diagram o Table B-1: Soil Vapor Extraction System Data o Table B-2: Soil Vapor Extraction System Influent Analytical Results o Table B-3: Soil Vapor Extraction System Effluent Analytical Results

• Appendix C - Groundwater Monitoring Data o Table C-1: Groundwater Monitoring Report

• Appendix D - Soil Vapor Sampling Data o Table D-1: Soil Vapor Monitoring Report

• Appendix E - Vapor Mitigation System Data o Table E-1 VMS Monitoring Data

• Appendix F - Mann Kendall Statistical Analysis

Semi-Annual Progress Report Former Chevron Facility No. 122208, Chillum, Maryland July through December 2009

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2.0 WORK CONDUCTED DURING THE REPORTING PERIOD This section provides a summary of work conducted at the site during the reporting period. 2.1 Site Monitoring Work Conducted The EPA-approved Interim Monitoring Sampling Plan calls for monthly gauging of ten monitoring wells, semi-annual gauging of all monitoring wells, semi-annual sampling of 72 monitoring wells, and semi-annual sampling of the four soil vapor wells (Table 1). Monthly groundwater gauging was conducted on July 27, August 24, September 14 (semi-annual), October 28, November 16, and December 22, 2009. The semi-annual groundwater sampling event was conducted from September 21 through September 29, 2009. Semi-annual soil vapor sampling was conducted on September 17, 2009. 2.2 Interim Measures Conducted Interim measures activities were conducted during the reporting period. These activities are listed below followed by a general description:

• Continued operation and maintenance of the Interim Dual Phase Extraction System (IDPES).

Overview of the Interim Dual Phase Extraction System The IDPES consists of total fluids extraction and treatment, and soil vapor extraction and treatment. The process and instrumentation diagram (P&ID) for the system (Appendix A) provides specific system information, such as equipment models and sizes, piping sizes, controls, and other technical information. Total Fluids Recovery and Treatment Pneumatic total fluids (i.e., groundwater and Liquid Phase Hydrocarbons [LPH], if present) pumps are installed in seven Dual Phase Extraction (DPE) wells (RW-1, RW-2, RW-3, MW-7, MW-17, PTW-A, and PTW-B). Total fluids are pumped from wells through buried piping to the total fluids manifold located in the treatment system compound, adjacent to the service station. The total fluids manifold leads to a coalescing-type oil/water separator. Level sensors in the oil/water separator control a centrifugal pump that intermittently transfers the water to an air stripper. LPH accumulate in the separator and are periodically skimmed off mechanically (if present). Air from the air stripper is treated using three granular activated carbon (GAC) vessels in parallel and then discharges to the atmosphere in accordance with MDE Air Quality General Permit to Construct Identification No. 033-9-1160. Treated water from the air stripper is pumped through two bag filters and then through six GAC vessels arranged in three parallel banks of two. Each bank is composed of two GAC vessels in series. The polished effluent flows through buried pipe to a storm drain inlet located in Riggs Road near the intersection at Eastern Avenue, N.E. in accordance with Maryland General Discharge Permit No. 2008 OGR-8514.


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Soil Vapor Recovery and Treatment Soil vapor extraction (SVE) is conducted at eight wells (i.e., the seven DPE wells plus MP-7). An individual piping leg runs from each well to a common 3-inch manifold in the remediation system compound. The manifold leads to a moisture knockout tank and then to the blower. The blower is a rotary lobe, positive displacement blower controlled by a variable frequency drive. Soil vapor is blown from the blower to a catalytic oxidizer for treatment. Treated air is discharged to the atmosphere in accordance with MDE Air Quality General Permit to Construct Identification No. 033-9-1164. Interim DPE System Monitoring The IDPES was visited every week during the reporting period. The following activities were conducted during each site visit:

• Recorded groundwater and air flow rates; • Measured air influent and effluent concentrations using a flame ionization detector;

• Recorded the manifold vacuum for the SVE system; and

• Conducted equipment maintenance tasks as needed, including checking the oil level of

the SVE blower and air compressor, changing out the bag filters, and skimming off LPH in the oil/water separator, if present.

The groundwater influent (SP-1) was sampled 5 times and the effluent (SP-3) was sampled 22 times for laboratory analysis (Appendix A). Effluent groundwater samples were analyzed by EPA Method 8260 for benzene, toluene, ethylbenzene, and xylenes (BTEX), methyl tert-butyl ether (MTBE), tetrachloroethene, trichloroethene, and 1,2-cis-dichloroethene. The permit limits are 100 μg/L for total BTEX and 5 μg/L for benzene. The discharge permit requires reporting of MTBE, tetrachloroethene, trichloroethene, and 1,2-cis-dichloroethene concentrations without establishing limits. The soil vapor extraction system influent (SP-100) and effluent (SP-200) were sampled three times for laboratory analysis during the reporting period to document compliance with the air discharge permit (Appendix B). Treated effluent (treated air) sampling port (SP-200) is located in the catalytic oxidizer effluent stack before discharge to the atmosphere. Samples were analyzed by EPA Method TO-3 for BTEX and total recoverable petroleum hydrocarbons (TRPH) in the C4 to C10 range. The air permit discharge limits are 20 pounds of volatile organic compounds per day and 0.02 pounds of benzene per hour. Operations and Maintenance of Vapor Mitigation Systems (VMS) Three VMS systems at 5818 Eastern Avenue, 5824 Eastern Avenue, and 746 Oglethorpe Street were monitored during the reporting period. The VMS located at 5824 Eastern Avenue and 5818 Eastern Avenue were monitored in the third quarter on August 24, 2009. The VMS at 746 Oglethorpe Street was started on March 31, 2009 and was then turned off by the resident. It was restarted on October 19, 2009 and monthly monitoring was conducted on October 19, and November 16, 2009. Due to scheduling conflicts with the resident, monthly monitoring in December was not conducted.


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Typical inspection and monitoring tasks included:

• Listening to the fan to ensure that it was running properly (no abnormal sounds); • Ensuring that the knife valve was locked open; • Ensuring that the electrical box was locked; • Inspecting the discharge pipes for evidence of superficial damage; • Ensuring that there were no damaged or exposed electrical wires; • Inspecting the vent stack for proper attachment to the building wall; • Confirming that the condensate drain was not blocked (e.g., with ice); • Taking measurements of the air velocity and flow from the discharge stack; and • Taking measurements of the cross-slab pressure differential.

2.3 Corrective Measures Conducted The following Corrective Measures activities were conducted during this period:

• The final Corrective Measures Implementation Work Plan was submitted to EPA and subsequently approved. Design activities commenced.

• Area A DPE System Expansion: The design plan was submitted to EPA for review in December.

• Area B ISGR Wells: Permits were obtained for the pre-design investigation. The investigation will be conducted in January 2010. Design activities were initiated.

• Area C Oxygen Reactive Zone: The design plan was submitted to EPA for review in October. EPA conditionally approved the plan, but required removal of the vault ventilation blower. The design was in the process of being modified to remove the blower from the plans and specifications during the reporting period.

2.4 Submittal of Deliverables Chevron submitted the following deliverables to EPA during the reporting period.

• Semi-Annual Progress Report for January through June 2009 on July 17, 2009;

• Corrective Measures Implementation Work Plan on August 14, 2009;

• Corrective Measures Implementation Design Plan: Area C Oxygen Reactive Zone on October 15, 2009; and

• Corrective Measures Implementation Design Plan: Area A Dual Phase Extraction

System Expansion on December 14, 2009 Oxygen Reactive Zone on October 15, 2009.


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3.0 SUMMARY OF FINDINGS This section provides a summary of findings and results for the interim measures activities described in Section 2.2. Ongoing Operation of the DPE System The hour meters for both the total fluids and SVE portions of the DPE system were logged throughout the period. For the period from July 1, 2009 through December 31, 2009, the total fluids extraction portion of the system was operating 77 percent of the time (3,368 hours on and 1,021 hours off) and the SVE portion was operating 29 percent of the time (1,274 hours on and 3,082 hours off). Table A-1 in Appendix A contains groundwater extraction system performance data including date and time, on/off status, totalizer reading, cumulative gallons of hydrocarbons, operating extraction points, maintenance information for the reporting period and the previous period (January 1, 2009 through December 31, 2009), comments on the reason for system downtime, and the type of maintenance performed . A detailed explanation of the tables is provided on the first page of Appendix A. A P&ID is also included in Appendix A. The groundwater extraction portion of the DPE system pumped approximately 3,279,778 gallons of groundwater and recovered 40.2 equivalent gallons of dissolved hydrocarbons during the reporting period. The average system flow rate over the period was 16.2 gallons per minute (gpm) when the system was pumping (not including system down time) and 12.5 gpm for the entire period (including down time). The total volume of groundwater pumped from this site since remediation began in 1989 is approximately 48,385,322 gallons. The analytical results for groundwater samples collected at sample points SP-1 (system influent) (Table A-2 in Appendix A) and SP-3 (treated groundwater that is discharged to the storm drain) (Table A-3 in Appendix A) indicated concentrations of benzene and BTEX in the treated groundwater were below the permit limits (5 μg/L benzene and 100 μg/L BTEX) during the reporting period. Tables B-1, B-2, and B-3 in Appendix B contain the soil vapor extraction system performance data collected for the reporting period including date and time, manifold air flow reading, manifold vacuum reading, influent and effluent screening concentrations measured using a FID, cumulative gallons of hydrocarbons recovered, and other information. A detailed explanation of the tables is provided on the first page of Appendix B. The P&ID is included in Appendix A. The soil vapor extraction portion of the DPE system recovered 112 equivalent gallons of hydrocarbons in the vapor phase during the reporting period. The average air flow rate was 136.4 standard cubic feet per minute (scfm) when the system was on (excluding down time) and 39.9 scfm for the entire period (including down time). The laboratory analytical results for monthly SVE system samples collected at sample points SP-100 (soil vapor influent) (Appendix B, Table B-2) and SP-200 (treated soil vapor that is discharged to the atmosphere) (Appendix B, Table B-3) indicated concentrations of benzene and TRPH in the treated soil vapor were well below the permit limits. The permit limits are


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0.02 pounds per hour of benzene and 20 pounds per day of volatile organic compounds measured as TRPH. Hydrocarbon Recovery Summary for Period and Cumulative Total for System

Period Liquid-Phase Hydrocarbons

(gallons)

Dissolved-Phase

Hydrocarbons (eq. gallons)

Vapor-Phase Hydrocarbons(eq. gallons)

Cumulative Total

Hydrocarbons(eq. gallons)

07/01/09-12/31/09 0.00 40.2 112.1 152.3

Cumulative Total for System

856.5 785.8 3,982.0 5,624.3

The volume of groundwater treated and the corresponding volume of hydrocarbons collected for the entire time the system has been operating on a quarter by quarter basis continued to be tracked (Figure 1). Groundwater Monitoring The analytical data from the September 2009 semi-annual sampling event and the groundwater elevation data for the current period and the previous period are provided in Table C-1 in Appendix C. A detailed explanation of the table is provided on the first page of Appendix C. Groundwater concentration maps were created using data collected during the September 2009 semi-annual sampling event (Figures 2 through 7). Passive Sampling Using the HydraSleeve™ During the September 2009 sampling event, two samples were collected at select wells. One sample was collected using the HydraSleeve passive sampler and a second sample was collected using the regular bailer sampling approach immediately following the passive sampling so that the two sampling methods could be compared (Table 2). Based on the analytical results and field team observations during sampling, several conclusions can be drawn:

• The use of the Hydrasleeve was limited in wells with short water columns (i.e., wells with less than 3 feet of water) because the sampler would not retrieve enough water for the sample bottleware;

• HydraSleeve does not make a sampler for wells smaller than 1-inch in diameter. Therefore, the ¾ -inch wells at the site cannot be sampled using Hydrasleeve;

• HydraSleeve sampling takes approximately half the time of bailer sampling;

• The analytical results were comparable for all wells excluding MW-15 (Table 2);


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• MW-15 has a 40-foot long screen that had 20 feet of water in the well at the time of sampling. The discrepancy in sampling results is likely due to water column stratification within the well. Hydrocarbons are entering the well at a different elevation in the well than where the HydraSleeve was suspended. Therefore, the HydraSleeve may not provide comparable analytical results for wells with water columns over 15 feet in length.

Based on these findings, Chevron recommends that future sampling events utilize the passive HydraSleeve sampling in place of bailer sampling at thirty-three groundwater wells that meet the following critera (Table 1). Criteria used to select wells to be sampled using HydraSleeve samplers:

• A water column of a minimum of 4 feet so that the required sample volume can be collected;

• A water column maximum of 12 feet to prevent stratification; and

• A well diameter of 1 inch or greater.

Soil Vapor Monitoring The soil vapor analytical results for the current period and the previous year are provided in Table D-1 in Appendix D. Water was present in the tubing of soil vapor well VW-4 during the September 2009 sampling event; therefore, no sample was collected. Vapor Mitigation System Monitoring The vapor mitigation system monitoring results for the current period and previous period are provided in Table E-1 in Appendix E. All cross-slab differential pressure readings during this period were sufficiently negative at all three residences, indicating that the systems were operating as designed. Mann-Kendall Statistical Analysis The Mann-Kendall Statistical Analysis report is provided in Appendix F. The results of the analysis indicated that dissolved-phase hydrocarbons were either stable or decreasing.


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4.0 PERMIT COMPLIANCE Four permits are required for activities performed at the Chillum site. Two air discharge permits have been issued by MDE covering the effluent of the groundwater air stripping equipment and the effluent of the soil vapor extraction equipment. In addition, another permit was issued by MDE for discharge of treated groundwater. Permit requirements and compliance for the above MDE permits are discussed in Sections 2 and 3. An additional permit required for work in Washington, D.C. is issued by the D.C. Department of Transportation (DCDOT) for Above Ground Public Space occupancy to perform activities such as sampling and gauging of monitoring wells. Permit numbers 033-9-1160 Air Quality General Permit for effluent of groundwater air stripping equipment and 033-9-1164 Air Quality General Permit for effluent of soil vapor extraction equipment were issued for the site. Neither of these permits has an expiration date. Sampling and monitoring requirements include periodic effluent monitoring as described in Sections 2 and 3. Permit number 2008-OGR-8514 General Discharge Permit was issued for treated groundwater discharge at the site. This permit became effective on January 31, 2008, and expires on December 12, 2012. The permit requires weekly effluent sampling, system monitoring, and submission of a quarterly Discharge Monitoring Report. Permit number PA 41221-R2 for Above Ground Public Space Occupancy was issued to cover traffic control requirements for sampling and gauging. The permit was renewed on August 27, 2009, and expires March 2, 2010. Permit number PA 52094 Public Space Subsurface for the pre-design investigation of Area B was issued by the DCDOT on January 6, 2010.


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5.0 Summary of Deviations from Approved Plans, Problems Encountered, and Corrective Actions Taken

• The vapor mitigation system at 746 Oglethorpe Street was turned off by the resident

after receiving a larger than normal electric bill that was not due to the vapor mitigation system. EPA and DDOE were notified of this situation in writing on April 21, 2009, after Chevron was notified by the resident. The resident resolved the billing issue with the electric company, PEPCO, in October and turned the system back on. Chevron monitored the system monthly during October and November 2009. Scheduling conflicts with the resident precluded monitoring in December 2009.

• The SVE blower motor in the IDPES started shutting down regularly in June 2009.

After extensive troubleshooting over the period of approximately a month, it was determined that it was likely that the blower motor that needed to be replaced. Chevron replaced the blower motor on September 9, 2009.


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6.0 SUMMARY OF MEETINGS WITH PUBLIC AND GOVERNMENT No meetings were conducted.


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7.0 CHANGES IN KEY PERSONNEL DURING THE REPORTING PERIOD There were no changes in key Gannett Fleming or Chevron personnel.


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8.0 PROJECTED WORK FOR THE NEXT REPORTING PERIOD The following list identifies projected work to be conducted during the next reporting period, which is January through June 2010 (semi-annual reporting).

• Monthly monitoring of the IDPES including influent and effluent sampling;

• Weekly sampling of the IDPES effluent to comply with water discharge permits;

• Monthly gauging of select wells near the service station to check for the presence of

LPH and to document drawdown caused by the total fluids extraction system;

• Routine operations and maintenance activities for the remediation system and the vapor mitigation systems;

• Conduct the semi-annual groundwater and soil vapor sampling event at the end of March 2010;

• Annual system monitoring sampling for the vapor mitigation systems in February 2010;

• Conduct pre-design investigation for Area B;

• Submission of Corrective Measures Design Report for Area B; and

• Permitting and bidding for construction of remediation systems in Areas A and C.

TABLES

Table 1(1) Summary of Groundwater Gauging Plan

Groundwater and Soil Vapor Long Term Monitoring Plan Former Chevron Facility No. 122208, Chillum, Maryland

Table 1.doc Page 1 of 3 Printed on: 1/19/2010

Well Identifier Well Location Category

Petroleum Hydrocarbon

Sampling Frequency

Current Sampling Method

Proposed Future

Sampling Method

Groundwater Gauging

Frequency(2) Comment GP-27A Dual-Phase Extraction System Semi-annual(3) From pump From pump Monthly GP-30A Dual-Phase Extraction System Semi-annual From pump From pump Monthly GP-35A Dual-Phase Extraction System Semi-annual From pump From pump Monthly GP-38A Dual-Phase Extraction System Semi-annual From pump From pump Monthly

MP-7 Dual-Phase Extraction System None None None Monthly Gauge only MP-20 Dual-Phase Extraction System None None None Semi-annual Gauge only MP-30 Dual-Phase Extraction System None None None Semi-annual Gauge only MP-40 Dual-Phase Extraction System None None None Semi-annual Gauge only MW-5 Dual-Phase Extraction System Semi-annual From pump From pump Semi-annual MW-7 Dual-Phase Extraction System Semi-annual From pump From pump Monthly Recovery Well

MW-15 Dual-Phase Extraction System Semi-annual From pump From pump Semi-annual MW-16 Dual-Phase Extraction System Semi-annual From pump From pump Monthly MW-17 Dual-Phase Extraction System Semi-annual From pump From pump Semi-annual Recovery Well MW-18 Dual-Phase Extraction System Semi-annual From pump From pump Monthly MW-22 Dual-Phase Extraction System Semi-annual From pump From pump Monthly MW-23 Dual-Phase Extraction System Semi-annual From pump From pump Semi-annual PTW-A Dual-Phase Extraction System Semi-annual From pump From pump Semi-annual Recovery Well PTW-B Dual-Phase Extraction System Semi-annual From pump From pump Semi-annual Recovery Well RW-1 Dual-Phase Extraction System Semi-annual From pump From pump Semi-annual Recovery Well RW-2 Dual-Phase Extraction System Semi-annual From pump From pump Semi-annual Recovery Well RW-3 Dual-Phase Extraction System Semi-annual From pump From pump Semi-annual Recovery Well

GP-2E(45-50) Dissolved Hydrocarbons Semi-annual Bailer Bailer Semi-annual GP-2E(55-60) Dissolved Hydrocarbons Semi-annual Bailer Bailer Semi-annual GP-2F(45-50) Dissolved Hydrocarbons Semi-annual Bailer Bailer Semi-annual GP-2F(50-55) Dissolved Hydrocarbons Semi-annual Bailer Bailer Semi-annual GP-7A(30-35) Dissolved Hydrocarbons Semi-annual Bailer Bailer Semi-annual GP-7A(35-40) Dissolved Hydrocarbons Semi-annual Bailer Bailer Semi-annual

GP-24A Dissolved Hydrocarbons Semi-annual Bailer HydraSleeve Semi-annual GP-39A Dissolved Hydrocarbons Semi-annual Bailer HydraSleeve Semi-annual

Table 1 (Continued)




Sampling Frequency


Proposed Future

Sampling Method

Groundwater Gauging

Frequency(2) Comment GP-41A Dissolved Hydrocarbons Semi-annual Bailer HydraSleeve Semi-annual GP-44A Dissolved Hydrocarbons Semi-annual Bailer Bailer Semi-annual MW-24A Dissolved Hydrocarbons Semi-annual Bailer Bailer Monthly MW-24B Dissolved Hydrocarbons Semi-annual Bailer HydraSleeve Semi-annual MW-25A Dissolved Hydrocarbons Semi-annual Bailer Bailer Semi-annual MW-25B Dissolved Hydrocarbons Semi-annual Bailer HydraSleeve Semi-annual MW-26A Dissolved Hydrocarbons Semi-annual Bailer HydraSleeve Semi-annual MW-26B Dissolved Hydrocarbons Semi-annual Bailer HydraSleeve Semi-annual MW-27A Dissolved Hydrocarbons Semi-annual Bailer HydraSleeve Semi-annual MW-27B Dissolved Hydrocarbons Semi-annual Bailer HydraSleeve Semi-annual MW-33A Dissolved Hydrocarbons Semi-annual Bailer HydraSleeve Semi-annual Added at the request of EPA MW-33B Dissolved Hydrocarbons Semi-annual Bailer HydraSleeve Semi-annual MW-33C Dissolved Hydrocarbons Semi-annual Bailer HydraSleeve Semi-annual Added at the request of EPA MW-33S Dissolved Hydrocarbons Semi-annual Bailer Bailer Semi-annual MW-38 Dissolved Hydrocarbons Semi-annual Bailer HydraSleeve Semi-annual

MW-39R Dissolved Hydrocarbons Semi-annual Bailer Bailer Semi-annual MW-40 Dissolved Hydrocarbons Semi-annual Bailer HydraSleeve Semi-annual

MW-43B Dissolved Hydrocarbons Semi-annual Bailer HydraSleeve Semi-annual MW-44A Dissolved Hydrocarbons Semi-annual Bailer Bailer Semi-annual MW-44B Dissolved Hydrocarbons Semi-annual Bailer HydraSleeve Semi-annual MW-45 Dissolved Hydrocarbons Semi-annual Bailer HydraSleeve Semi-annual MW-46 Dissolved Hydrocarbons Semi-annual Bailer HydraSleeve Semi-annual MW-47 Dissolved Hydrocarbons Semi-annual Bailer Bailer Semi-annual MW-49 Dissolved Hydrocarbons Semi-annual Bailer HydraSleeve Semi-annual MW-50 Dissolved Hydrocarbons Semi-annual Bailer Bailer Semi-annual

GP-7A(20-25) Sentinel Semi-annual Bailer Bailer Semi-annual GP-9A(20-25) Sentinel Semi-annual Bailer Bailer Semi-annual GP-11A(20-25) Sentinel Semi-annual Bailer Bailer Semi-annual

MW-6 Sentinel Semi-annual Bailer HydraSleeve Semi-annual MW-19 Sentinel Semi-annual Bailer Bailer Semi-annual MW-20 Sentinel Semi-annual Bailer HydraSleeve Semi-annual Upgradient MW-21 Sentinel Semi-annual Bailer HydraSleeve Semi-annual

Table 1 (Continued)




Sampling Frequency


Proposed Future

Sampling Method

Groundwater Gauging

Frequency(2) Comment MW-28A Sentinel Semi-annual Bailer HydraSleeve Semi-annual MW-28B Sentinel Semi-annual Bailer HydraSleeve Semi-annual MW-29A Sentinel Semi-annual Bailer HydraSleeve Semi-annual MW-29B Sentinel Semi-annual Bailer HydraSleeve Semi-annual MW-30 Sentinel Semi-annual Bailer HydraSleeve Semi-annual Upgradient

MW-31B Sentinel Semi-annual Bailer HydraSleeve Semi-annual MW-41A Sentinel Semi-annual Bailer HydraSleeve Semi-annual MW-41B Sentinel Semi-annual Bailer HydraSleeve Semi-annual MW-42 Sentinel Semi-annual Bailer Bailer Semi-annual Upgradient

MW-43A Sentinel Semi-annual Bailer HydraSleeve Semi-annual MW-48 Sentinel Semi-annual Bailer Bailer Semi-annual MW-51 Sentinel Semi-annual Bailer Bailer Semi-annual MW-53 Sentinel Semi-annual Bailer HydraSleeve Semi-annual MW-54 Sentinel Semi-annual Bailer Bailer Semi-annual MW-55 Sentinel Semi-annual Bailer HydraSleeve Semi-annual VW-1 Soil Vapor Semi-annual NA NA Semi-annual VW-2 Soil Vapor Semi-annual NA NA Semi-annual VW-3 Soil Vapor Semi-annual NA NA Semi-annual VW-4 Soil Vapor Semi-annual NA NA Semi-annual

Footnotes: (1) This table is adapted from the Interim Measures Sampling Plan, dated April 2006.

(2) All wells will be gauged in the spring and the fall during the Semi-annual sampling events. (3) Sampling will be conducted in the spring and fall (low and high groundwater conditions).

Well ID

Screen Length

(ft)

Water Column

(ft) ParameterBailer(µg/L)

HydraSleeve™ (µg/L)

Benzene 9 11Toluene <1 <2Ethylbenzene <1 <2Xylenes <3 <6MTBE 160 220TPH-GRO Not Sampled 290Benzene 2,800 3,100Toluene 1,900 2,200Ethylbenzene 190 240Xylenes 990 1,100MTBE 4,700 4,600TPH-GRO Not Sampled 15,000Benzene 170 170Toluene <2 <2Ethylbenzene <2 <2Xylenes 27 29MTBE 240 260TPH-GRO 820 790Benzene 6,200 7,400Toluene 6,500 7,500Ethylbenzene 500 410Xylenes 3,600 3,600MTBE 13,000 15,000TPH-GRO 51,000 59,000Benzene 2 1Toluene 5 33Ethylbenzene 17 50Xylenes 51 168MTBE <1 <1TPH-GRO 890 1,700Benzene 7 1Toluene 32 <1Ethylbenzene 13 <1Xylenes 49 <3MTBE <1 <1TPH-GRO 680 <100

MW-151 40 20

MW-6

10

MW-25B

15 10

Table 2. Comparison of Results for the Bailing and Passive Sampling MethodsSemi Annual Progress Report July Through December 2009

10 20

GP-39A 20

GP-39A 20 10

MW-53

Former Chevron Facility No. 1222085801 Riggs Road, Chillum, Maryland

5 4

122208_Table 2.xls Page 1 of 2 Printed on: 1/14/2010

Well ID

Screen Length

(ft)

Water Column

(ft) ParameterBailer(µg/L)

HydraSleeve™ (µg/L)

Table 2. Comparison of Results for the Bailing and Passive Sampling MethodsSemi Annual Progress Report July Through December 2009


Benzene 3,500 4,200Toluene 9,600 12,000Ethylbenzene 960 1,100Xylenes 8,100 9,300MTBE 390 420TPH-GRO 50,000 55,000

Notes:1) MW-15 has a stratified water column and the HydraSleeve was not suspended at an elevation where hydrocarbons are present. HydraSleeve sampling method is not recommended for wells with long screen lengths.

MW-22 20 12

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FIGURES

Figure 1

Cumulative Total Hydrocarbons Recovered and Groundwater Treated Since 1990

Semi-Annual Progress Report January 2009 Through December 2009

Former Chevron Facility 122208, Chillum, Maryland

500

1,000

1,500

2,000

2,500

3,000

3,500

4,000

4,500

5,000

5,500

1Q92

4Q92

3Q93

2Q94

1Q95

4Q95

3Q96

2Q97

1Q98

4Q98

3Q99

2Q00

1Q01

4Q01

3Q02

2Q03

1Q04

4Q04

3Q05

2Q06

1Q07

4Q07

3Q08

2Q09

Time

Cu

mu

lati

ve T

ota

l H

yd

rocarb

on

s R

eco

vere

d

(eq

. g

all

on

s)

0

2,000,000

4,000,000

6,000,000

8,000,000

10,000,000

12,000,000

14,000,000

16,000,000

18,000,000

20,000,000

22,000,000

24,000,000

26,000,000

28,000,000

30,000,000

32,000,000

34,000,000

36,000,000

38,000,000

40,000,000

42,000,000

44,000,000

To

tal

Gro

un

dw

ate

r T

reate

d (

gall

on

s)

Total Hydrocarbons Removed Groundwater Treated

DPE System started

1990 - LPH

Skimmer

System started DPE System shutdown to

evaluate non-pumping

groundwater conditions

Expanded

DPE System

started

DPE System shut

down for expansion

FIGURE 8: MW-18 BENZENE TREND ANALYSISSEMI-ANNUAL PROGRESS REPORT

JANUARY THROUGH JUNE 2009FORMER CHEVRON FACILITY 122208

5801 RIGGS ROAD, CHILLUM, MARYLAND

1

10

100

1,000

10,000

Oct-01

Jan-0

2Apr-

02Ju

l-02

Oct-02

Jan-0

3Apr-

03Ju

l-03

Oct-03

Jan-0

4Apr-

04Ju

l-04

Oct-04

Jan-0

5Apr-

05Ju

l-05

Oct-05

Jan-0

6Apr-

06Ju

l-06

Oct-06

Jan-0

7Apr-

07Ju

l-07

Oct-07

Jan-0

8Apr-

08Ju

l-08

Oct-08

Jan-0

9Apr-

09Ju

l-09

Oct-09

Date

Ben

zene

(µg/

L)(L

og)

134135136137138139140141142143144145146147148149150151152

Gro

undw

ater

Ele

vatio

n (ft

)

Benzene(µg/L)

Elevation (ft)

Screen29-44 ft bgsScreen Top: 139.45 ftScreen Bottom: 124.45 ft

ND : Not Detected above the reporting limit

ND ND ND N

FIGURE 9: MW-18 MTBE TREND ANALYSISSEMI-ANNUAL PROGRESS REPORT



1

10

100

1,000

Oct-01

Jan-0

2Apr-

02Ju

l-02

Oct-02

Jan-0

3Apr-

03Ju

l-03

Oct-03

Jan-0

4Apr-

04Ju

l-04

Oct-04

Jan-0

5Apr-

05Ju

l-05

Oct-05

Jan-0

6Apr-

06Ju

l-06

Oct-06

Jan-0

7Apr-

07Ju

l-07

Oct-07

Jan-0

8Apr-

08Ju

l-08

Oct-08

Jan-0

9Apr-

09Ju

l-09

Oct-09

Date

MTB

E (µ

g/L)

(Log

)

134135136137138139140141142143144145146147148149150151152

Gro

undw

ater

Ele

vatio

n (ft

)

MTBE (µg/L)

Elevation (ft)



ND ND ND

ND

ND

ND

ND

FIGURE 10: MW-24A BENZENE TREND ANALYSISSEMI-ANNUAL PROGRESS REPORT



1

10

100

1,000

Jun-0

4Sep

-04Dec

-04Mar-

05Ju

n-05

Sep-05

Dec-05

Mar-06

Jun-0

6Sep

-06Dec

-06Mar-

07Ju

n-07

Sep-07

Dec-07

Mar-08

Jun-0

8Sep

-08Dec

-08Mar-

09Ju

n-09

Sep-09

Dec-09

Date

Ben

zene

(µg/

L)(L

og)

133

134

135

136

137

138

139

140

141

Gro

undw

ater

Ele

vatio

n (ft

)

Benzene(µg/L)

Elevation (ft)

Screen16-23.5 ft bgsScreen Top: 141.4 ftScreen Bottom: 133.9 ft


ND ND

FIGURE 11: MW-24A MTBE TREND ANALYSISSEMI-ANNUAL PROGRESS REPORT



1

10

Jun-04

Sep-04

Dec-04

Mar-05

Jun-05

Sep-05

Dec-05

Mar-06

Jun-06

Sep-06

Dec-06

Mar-07

Jun-07

Sep-07

Dec-07

Mar-08

Jun-08

Sep-08

Dec-08

Mar-09

Jun-09

Sep-09

Dec-09

Date

MTB

E (µ

g/L)

(Log

)

134

135

136

137

138

139

140

Gro

undw

ater

Ele

vatio

n (ft

)

MTBE (µg/L)

Elevation (ft)

Screen16-23.5 ft bgsScreen Top: 141.4 ftScreen Bottom: 133.9 ft


ND ND ND ND ND ND ND ND

FIGURE 12: MW-24B BENZENE TREND ANALYSISSEMI-ANNUAL PROGRESS REPORT



1

10

100

1,000

Jun-0

4Sep

-04Dec

-04Mar-

05Ju

n-05

Sep-05

Dec-05

Mar-06

Jun-0

6Sep

-06Dec

-06Mar-

07Ju

n-07

Sep-07

Dec-07

Mar-08

Jun-0

8Sep

-08Dec

-08Mar-

09Ju

n-09

Sep-09

Dec-09

Date

Ben

zene

(µg/

L)(L

og)

135

136

137

138

139

140

Gro

undw

ater

Ele

vatio

n (ft

)

Benzene(µg/L)

Elevation (ft)

Screen22.5-30 ft bgsScreen Top: 134.95 ftScreen Bottom: 127.45 ft


ND

FIGURE 13: MW-24B MTBE TREND ANALYSISSEMI-ANNUAL PROGRESS REPORT



1

10

Jun-0

4Sep

-04Dec

-04Mar-

05Ju

n-05

Sep-05

Dec-05

Mar-06

Jun-0

6Sep

-06Dec

-06Mar-

07Ju

n-07

Sep-07

Dec-07

Mar-08

Jun-0

8Sep

-08Dec

-08Mar-

09Ju

n-09

Sep-09

Dec-09

Date

MTB

E (µ

g/L)

(Log

)

135

136

137

138

139

140

Gro

undw

ater

Ele

vatio

n (ft

)

MTBE (µg/L)

Elevation (ft)

Screen22.5-30 ft bgsScreen Top: 134.95 ftScreen Bottom: 127.45 ft


ND ND NDND

NDND

FIGURE 14: GP-2E (45-50) BENZENE TREND ANALYSISSEMI-ANNUAL PROGRESS REPORT



1

10

100

1,000

Apr-02

Jul-0

2Oct-

02Ja

n-03

Apr-03

Jul-0

3Oct-

03Ja

n-04

Apr-04

Jul-0

4Oct-

04Ja

n-05

Apr-05

Jul-0

5Oct-

05Ja

n-06

Apr-06

Jul-0

6Oct-

06Ja

n-07

Apr-07

Jul-0

7Oct-

07Ja

n-08

Apr-08

Jul-0

8Oct-

08Ja

n-09

Apr-09

Jul-0

9Oct-

09

Date

Ben

zene

(µg/

L)(L

og)

123

124

125

126

127

128

Gro

undw

ater

Ele

vatio

n (ft

)

Benzene(µg/L)

Elevation (ft)



ND ND

FIGURE 15: GP-2E (45-50) MTBE TREND ANALYSISSEMI-ANNUAL PROGRESS REPORT



1

10

100

1,000

Apr-02

Jul-0

2Oct-

02Ja

n-03

Apr-03

Jul-0

3Oct-

03Ja

n-04

Apr-04

Jul-0

4Oct-

04Ja

n-05

Apr-05

Jul-0

5Oct-

05Ja

n-06

Apr-06

Jul-0

6Oct-

06Ja

n-07

Apr-07

Jul-0

7Oct-

07Ja

n-08

Apr-08

Jul-0

8Oct-

08Ja

n-09

Apr-09

Jul-0

9Oct-

09

Date

MTB

E (µ

g/L)

(Log

)

123

124

125

126

127

128

Gro

undw

ater

Ele

vatio

n (ft

)

MTBE (µg/L)

Elevation (ft)



FIGURE 16: GP-2E (55-60) BENZNE TREND ANALYSISSEMI-ANNUAL PROGRESS REPORT



1

10

100

1,000

10,000

Apr-02

Jul-0

2Oct-

02Ja

n-03

Apr-03

Jul-0

3Oct-

03Ja

n-04

Apr-04

Jul-0

4Oct-

04Ja

n-05

Apr-05

Jul-0

5Oct-

05Ja

n-06

Apr-06

Jul-0

6Oct-

06Ja

n-07

Apr-07

Jul-0

7Oct-

07Ja

n-08

Apr-08

Jul-0

8Oct-

08Ja

n-09

Apr-09

Jul-0

9Oct-

09

Date

Ben

zene

(µg/

L)(L

og)

120

121

122

123

124

125

126

127

128

129

130

Gro

undw

ater

Ele

vatio

n (ft

)

Benzene(µg/L)

Elevation (ft)



NDND

FIGURE 17: GP-2E (55-60) MTBE TREND ANALYSISSEMI-ANNUAL PROGRESS REPORT



1

10

100

1,000

10,000

Apr-02

Jul-0

2Oct-

02Ja

n-03

Apr-03

Jul-0

3Oct-

03Ja

n-04

Apr-04

Jul-0

4Oct-

04Ja

n-05

Apr-05

Jul-0

5Oct-

05Ja

n-06

Apr-06

Jul-0

6Oct-

06Ja

n-07

Apr-07

Jul-0

7Oct-

07Ja

n-08

Apr-08

Jul-0

8Oct-

08Ja

n-09

Apr-09

Jul-0

9Oct-

09

Date

MTB

E (µ

g/L)

(Log

)

120

121

122

123

124

125

126

127

128

129

130

Gro

undw

ater

Ele

vatio

n (ft

)

MTBE (µg/L)

Elevation (ft)



FIGURE 18: GP-2F (45-50) BENZENE TREND ANALYSISSEMI-ANNUAL PROGRESS REPORT



1

10

100

Apr-02

Jul-0

2Oct-

02Ja

n-03

Apr-03

Jul-0

3Oct-

03Ja

n-04

Apr-04

Jul-0

4Oct-

04Ja

n-05

Apr-05

Jul-0

5Oct-

05Ja

n-06

Apr-06

Jul-0

6Oct-

06Ja

n-07

Apr-07

Jul-0

7Oct-

07Ja

n-08

Apr-08

Jul-0

8Oct-

08Ja

n-09

Apr-09

Jul-0

9Oct-

09

Date

Ben

zene

(µg/

L)(L

og)

113

114

115

116

117

118

119

120

Gro

undw

ater

Ele

vatio

n (ft

)

Benzene(µg/L)

Elevation (ft)



ND

ND ND ND ND ND ND ND ND

FIGURE 19: GP-2F (45-50) MTBE TREND ANALYSISSEMI-ANNUAL PROGRESS REPORT



1

10

100

1,000

Apr-02

Jul-0

2Oct-

02Ja

n-03

Apr-03

Jul-0

3Oct-

03Ja

n-04

Apr-04

Jul-0

4Oct-

04Ja

n-05

Apr-05

Jul-0

5Oct-

05Ja

n-06

Apr-06

Jul-0

6Oct-

06Ja

n-07

Apr-07

Jul-0

7Oct-

07Ja

n-08

Apr-08

Jul-0

8Oct-

08Ja

n-09

Apr-09

Jul-0

9Oct-

09

Date

MTB

E (µ

g/L)

(Log

)

113

114

115

116

117

118

119

120

Gro

undw

ater

Ele

vatio

n (ft

)

MTBE (µg/L)

Elevation (ft)



FIGURE 20: GP-2F (50-55) BENZENE TREND ANALYSISSEMI-ANNUAL PROGRESS REPORT



1

10

100

1,000

Apr-02

Jul-0

2Oct-

02Ja

n-03

Apr-03

Jul-0

3Oct-

03Ja

n-04

Apr-04

Jul-0

4Oct-

04Ja

n-05

Apr-05

Jul-0

5Oct-

05Ja

n-06

Apr-06

Jul-0

6Oct-

06Ja

n-07

Apr-07

Jul-0

7Oct-

07Ja

n-08

Apr-08

Jul-0

8Oct-

08Ja

n-09

Apr-09

Jul-0

9Oct-

09

Date

Ben

zene

(µg/

L)(L

og)

113

114

115

116

117

118

Gro

undw

ater

Ele

vatio

n (ft

)

Benzene(µg/L)

Elevation (ft)



ND

FIGURE 21: GP-2F (50-55) MTBE TREND ANALYSISSEMI-ANNUAL PROGRESS REPORT



1

10

100

1,000

Apr-02

Jul-0

2Oct-

02Ja

n-03

Apr-03

Jul-0

3Oct-

03Ja

n-04

Apr-04

Jul-0

4Oct-

04Ja

n-05

Apr-05

Jul-0

5Oct-

05Ja

n-06

Apr-06

Jul-0

6Oct-

06Ja

n-07

Apr-07

Jul-0

7Oct-

07Ja

n-08

Apr-08

Jul-0

8Oct-

08Ja

n-09

Apr-09

Jul-0

9Oct-

09

Date

MTB

E (µ

g/L)

(Log

)

113

114

115

116

117

118

Gro

undw

ater

Ele

vatio

n (ft

)

MTBE (µg/L)

Elevation (ft)



FIGURE 22: MW-33B BENZENE TREND ANALYSISSEMI-ANNUAL PROGRESS REPORT



1

10

100

1,000

10,000

May-04

Aug-04

Nov-04

Feb-05

May-05

Aug-05

Nov-05

Feb-06

May-06

Aug-06

Nov-06

Feb-07

May-07

Aug-07

Nov-07

Feb-08

May-08

Aug-08

Nov-08

Feb-09

May-09

Aug-09

Nov-09

Date

Ben

zene

(µg/

L)(L

og)

120

121

122

123

Gro

undw

ater

Ele

vatio

n (ft

)

Benzene(µg/L)

Elevation (ft)



ND

FIGURE 23: MW-33B MTBE TREND ANALYSISSEMI-ANNUAL PROGRESS REPORT



1

10

100

1,000

10,000

May-04

Aug-04

Nov-04

Feb-05

May-05

Aug-05

Nov-05

Feb-06

May-06

Aug-06

Nov-06

Feb-07

May-07

Aug-07

Nov-07

Feb-08

May-08

Aug-08

Nov-08

Feb-09

May-09

Aug-09

Nov-09

Date

MTB

E (µ

g/L)

(Log

)

120

121

122

123

Gro

undw

ater

Ele

vatio

n (ft

)

MTBE (µg/L)

Elevation (ft)



FIGURE 24: MW-33S BENZENE TREND ANALYSISSEMI-ANNUAL PROGRESS REPORT



1

10

100

1,000

10,000

May-05

Aug-05

Nov-05

Feb-06

May-06

Aug-06

Nov-06

Feb-07

May-07

Aug-07

Nov-07

Feb-08

May-08

Aug-08

Nov-08

Feb-09

May-09

Aug-09

Nov-09

Date

Ben

zene

(µg/

L)(L

og)

122

123

124

125

126

Gro

undw

ater

Ele

vatio

n (ft

)

Benzene(µg/L)

Elevation (ft)



ND ND ND ND ND ND ND NDNDND

FIGURE 25: MW-33S MTBE TREND ANALYSISSEMI-ANNUAL PROGRESS REPORT



1

10

100

1,000

10,000

May-05

Aug-05

Nov-05

Feb-06

May-06

Aug-06

Nov-06

Feb-07

May-07

Aug-07

Nov-07

Feb-08

May-08

Aug-08

Nov-08

Feb-09

May-09

Aug-09

Nov-09

Date

MTB

E (µ

g/L)

(Log

)

122

123

124

125

126

Gro

undw

ater

Ele

vatio

n (ft

)

MTBE (µg/L)

Elevation (ft)



NDNDND ND ND NDND NDND ND

APPENDIX A

DUAL-PHASE EXTRACTION SYSTEM – TOTAL FLUIDS EXTRACTION DATA

APPENDIX A

DUAL-PHASE EXTRACTION SYSTEM – TOTAL FLUIDS EXTRACTION DATA

DESCRIPTION OF DATA TABLES Chevron uses a central database to store remediation system data and laboratory analytical data. The tabulated data in Tables A-1, A-2, and A-3 is an exported summary of the total fluids extraction system data from the database. These data were recorded by the field technician during site visits. The analytical data for influent samples collected for laboratory analysis (Table A-2) are used to calculate the mass (and to estimate the volume) of hydrocarbons recovered in the dissolved phase. Effluent sample data are included in Table A-3 for comparison with permit limits. The data table includes all system data collected since January 1, 2009. Data collected prior to this date are available in previous progress reports. The following table lists the column headings in the table with a brief description of each. Please refer to the Process and Instrumentation Diagram (next page) for a schematic of equipment and sample ports. Column Heading Description Date / Time Date and time data were recorded. System Status System ON or OFF when technician recorded the data. Influent BTEX (μg/L) Sum of benzene, toluene, ethylbenzene, and total xylenes

from influent sample port SP-1. Effluent BTEX (μg/L) Sum of benzene, toluene, ethylbenzene, and total xylenes

from effluent sample port SP-3. Treatment Efficiency (%) Equation: (Influent-Effluent) / (Influent). Totalizer Reading (gallons) Reading on the totalizing flow meter. Pumped Period (gallons) Equation: (current totalizer reading) – (previous totalizer

reading). Pumped Total (gallons) Cumulative total gallons of groundwater recovered. Period Average (GPM) Equation: (Gallons Pumped During Period) / (current

Date-Time – previous Date-Time) Hydrocarbons Recovered Period (gallons)1

Equation: [Avg. Influent BTEX (ug/L)] * e^6 * (1/0.2) * (3.785 L/gal) * (1 lb/453.6 g) * (gallons pumped) * (1 gal/6.26 lbs). NOTE: Formula assumes BTEX equals 20% of gasoline.

Hydrocarbons Recovered Cumulative (gallons)

Equation: (Hydrocarbons Recovered During Period) + (Previous Cumulative)

Operating Extraction Points Wells in operation during the reporting period. Notes (1) Assumptions: BTEX is 20% of hydrocarbon product by volume; density of hydrocarbon product is 6.26 pounds/gallon. The Average (Avg.) Influent BTEX concentration is defined as the mean of the influent concentration for the current and previous sampling events.

Influent Effluent Treatment Totalizer Period Total PeriodSystem BTEX BTEX Efficiency Reading Pumped Pumped Average Period Cumul.

Date/Time Status (µg/L) (µg/L) (%) (gallons) (gallons) (gallons) (GPM) (gallons) (gallons) Operating Extraction Points1/5/09 11:25 ON 511 0 100.0 30,000,500 87,300 40,533,222 12.38 3.62 727.48 RW1 RW2 RW3 MW7 MW17 PTWA PTWB1/12/09 14:15 ON NS 0 - 30,221,700 221,200 40,754,422 21.58 - 727.48 RW1 RW2 RW3 MW7 MW17 PTWA PTWB1/19/09 10:15 ON NS 0 - 30,435,700 214,000 40,968,422 21.75 - 727.48 RW1 RW2 RW3 MW7 MW17 PTWA PTWB1/26/09 12:05 ON NS 0 - 30,656,700 221,000 41,189,422 21.69 - 727.48 RW1 RW2 RW3 MW7 MW17 PTWA PTWB2/2/09 7:55 ON 948 0 100.0 30,866,200 209,500 41,398,922 21.31 4.21 731.69 RW1 RW2 RW3 MW17 PTWA PTWB2/9/09 8:20 OFF NS NS - 31,005,700 139,500 41,538,422 13.81 - 731.69 Off to troubleshoot leaking well vault2/9/09 8:50 ON NS 0 - 31,005,700 0 41,538,422 0.00 - 731.69 RW1 RW2 RW3 MW17 PTWB2/16/09 10:10 OFF NS NS - 31,099,500 93,800 41,632,222 9.23 - 731.69 Off for routine maintenance2/16/09 16:10 ON NS 0 - 31,099,500 0 41,632,222 0.00 - 731.69 RW1 RW2 RW3 MW7 MW17 PTWA PTWB2/23/09 18:22 OFF NS NS - 31,315,600 216,100 41,848,322 21.16 - 731.69 Low pressure air compressor - tripped motor

starter2/24/09 10:00 ON NS 0 - 31,315,600 0 41,848,322 0.00 - 731.69 RW1 RW2 RW3 MW7 MW17 PTWA PTWB3/2/09 8:55 ON 550 0 100.0 31,506,300 190,700 42,039,022 22.24 3.20 734.89 RW1 RW2 RW3 MW7 MW17 PTWA PTWB3/4/09 6:45 OFF NS NS - 31,563,800 57,500 42,096,522 20.91 - 734.89 Low pressure air compressor - tripped motor

starter3/5/09 12:40 ON NS NS - 31,563,800 0 42,096,522 0.00 - 734.89 RW1 RW2 RW3 MW7 MW17 PTWA PTWB3/9/09 10:32 ON NS 0 - 31,680,500 116,700 42,213,222 20.72 - 734.89 RW1 RW2 RW3 MW7 MW17 PTWA PTWB3/12/09 11:20 OFF NS NS - 31,772,100 91,600 42,304,822 20.97 - 734.89 Off on OWS-HH3/12/09 15:20 ON NS NS - 31,772,100 0 42,304,822 0.00 - 734.89 RW1 RW2 RW3 MW7 MW17 PTWA PTWB3/16/09 8:25 OFF NS NS - 31,884,900 112,800 42,417,622 21.10 - 734.89 Off to clean air stripper3/16/09 12:15 ON NS NS - 31,884,900 0 42,417,622 0.00 - 734.89 RW1 RW2 RW3 MW7 MW17 PTWA PTWB3/16/09 13:30 OFF NS NS - 31,886,100 1,200 42,418,822 16.00 - 734.89 Off on AST_HH (clogged bag filters)3/16/09 13:50 ON NS 0 - 31,886,100 0 42,418,822 0.00 - 734.89 RW1 RW2 RW3 MW7 MW17 PTWA PTWB3/19/09 15:40 OFF NS NS - 31,977,800 91,700 42,510,522 20.70 - 734.89 AST-HH (clogged bag filters)3/23/09 10:50 ON NS 0 - 31,977,800 0 42,510,522 0.00 - 734.89 RW1 RW2 RW3 MW7 MW17 PTWA PTWB3/24/09 8:30 OFF NS NS - 31,994,900 17,100 42,527,622 13.15 - 734.89 Comp-Lo Compressor Needs to be Replaced5/5/09 12:15 ON NS NS - 31,994,900 0 42,527,622 0.00 - 734.89 RW1 RW2 RW3 MW7 MW17 PTWA PTWB5/11/09 7:00 OFF NS NS - 32,055,600 60,700 42,588,322 7.29 - 734.89 Comp_Lo - Auto drain on compressor Replaced

5/11/09 12:30 ON 3,120 0 100.0 32,055,600 0 42,588,322 0.00 6.72 741.60 RW1 RW2 RW3 MW7 MW17 PTWA PTWB5/18/09 9:30 OFF NS NS - 32,059,900 4,300 42,592,622 0.43 - 741.60 Comp_Lo5/18/09 15:15 ON NS NS - 32,059,900 0 42,592,622 0.00 - 741.60 RW1 RW2 RW3 MW7 MW17 PTWA PTWB5/20/09 10:28 OFF NS NS - 32,075,500 15,600 42,608,222 6.02 - 741.60 SUMP - Off for OWS plumbing repairs5/20/09 14:42 ON NS NS - 32,075,500 0 42,608,222 0.00 - 741.60 RW1 RW2 RW3 MW7 MW17 PTWA PTWB5/26/09 7:30 OFF NS NS - 32,079,700 4,200 42,612,422 0.51 - 741.60 VFD High AMP fault5/26/09 7:59 ON NS 0 - 32,079,700 0 42,612,422 0.00 - 741.60 RW1 RW2 RW3 MW7 MW17 PTWA PTWB5/30/09 23:59 ON NS NS - 32,134,938 55,238 42,667,660 8.22 - 741.60 Estimated6/3/09 9:00 ON NS NS - 32,211,300 76,362 42,744,022 15.71 - 741.60 RW1 RW2 RW3 MW7 MW17 PTWA PTWB6/3/09 10:30 OFF NS NS - 32,212,000 700 42,744,722 7.78 - 741.60 Off to replace fitting on OWS pump6/3/09 11:10 ON NS 0 - 32,212,000 0 42,744,722 0.00 - 741.60 RW1 RW2 RW3 MW7 MW17 PTWA PTWB6/8/09 7:59 OFF NS NS - 32,262,000 50,000 42,794,722 7.13 - 741.60 SUMP - Off for OWS plumbing repairs

Hydrocarbons Recovered

TABLE A-1: TOTAL FLUIDS EXTRACTION SYSTEM DATASEMI-ANNUAL PROGRESS REPORT: JULY THROUGH DECEMBER 2009FORMER CHEVRON FACILITY 122208, 5801 RIGGS ROAD, CHILLUM, MD

PERIOD: JANUARY 2009 - DECEMBER 2009

APP_ A_122208_4Q09_GWE 011410.xls Page 1 of 3 Printed on: 1/14/2010


Date/Time Status (µg/L) (µg/L) (%) (gallons) (gallons) (gallons) (GPM) (gallons) (gallons) Operating Extraction Points




6/8/09 10:20 ON NS 0 - 32,262,000 0 42,794,722 0.00 - 741.60 RW1 RW2 RW3 MW7 MW17 PTWA PTWB6/15/09 9:39 ON 975 0 100.0 32,353,000 91,000 42,885,722 9.06 4.06 745.66 RW1 RW2 RW3 MW7 MW17 PTWA PTWB6/22/09 7:15 ON NS 0 - 32,434,800 81,800 42,967,522 8.23 - 745.66 RW1 RW2 RW3 MW7 MW17 PTWA PTWB6/29/09 10:45 ON NS 0 - 32,520,000 85,200 43,052,722 8.28 - 745.66 RW1 RW2 RW3 MW7 MW17 PTWA PTWB7/1/09 16:20 ON NS NS - 32,553,122 33,122 43,085,844 10.30 - 745.66 estimated7/6/09 7:35 ON 0 0 - 32,600,600 47,478 43,133,322 7.11 0.00 745.66 RW1 RW2 RW3 MW7 MW17 PTWA PTWB7/6/09 7:41 OFF NS NS - 32,600,800 200 43,133,522 33.33 - 745.66 OFF to clean air stripper7/6/09 11:33 ON NS NS - 32,600,800 0 43,133,522 0.00 - 745.66 RW1 RW2 RW3 MW7 MW17 PTWA PTWB7/14/09 11:42 ON NS 0 - 32,695,900 95,100 43,228,622 8.25 - 745.66 RW1 RW2 RW3 MW7 MW17 PTWA PTWB7/20/09 7:10 ON NS NS - 32,764,900 69,000 43,297,622 8.25 - 745.66 RW1 RW2 RW3 MW7 MW17 PTWA PTWB7/20/09 7:22 OFF NS NS - 32,764,900 0 43,297,622 0.00 - 745.66 Shutdown for GAC changeout7/20/09 11:14 ON NS 0 - 32,764,900 0 43,297,622 0.00 - 745.66 RW1 RW2 RW3 MW7 MW17 PTWA PTWB7/27/09 10:35 ON NS 0 - 32,847,900 83,000 43,380,622 8.27 - 745.66 RW1 RW2 RW3 MW7 MW17 PTWA PTWB8/3/09 12:10 OFF NS NS - 32,929,000 81,100 43,461,722 7.97 - 745.66 Shut Down to change Air Compressor Oil8/3/09 12:25 ON NS 0 - 32,929,000 0 43,461,722 0.00 - 745.66 RW1 RW2 RW3 MW7 MW17 PTWA PTWB8/17/09 8:18 OFF NS NS - 33,009,500 80,500 43,542,222 4.04 - 745.66 Shut down on Compressor Low8/17/09 10:30 ON NS 0 - 33,009,500 0 43,542,222 0.00 - 745.66 RW1 RW2 RW3 MW7 MW17 PTWA PTWB8/24/09 10:40 ON 4,790 0 100.0 33,093,600 84,100 43,626,322 8.33 7.87 753.53 RW1 RW2 RW3 MW7 MW17 PTWA PTWB9/1/09 0:00 ON NS NS - 33,216,196 122,596 43,748,918 11.27 - 753.53 Estimated9/2/09 8:15 ON NS 0 - 33,238,000 21,804 43,770,722 11.27 - 753.53 RW1 RW2 RW3 MW7 MW17 PTWA PTWB9/9/09 8:36 OFF 4,060 0 100.0 33,408,500 170,500 43,941,222 16.88 9.29 762.82 Off on AST_HH (clogged bag filters)9/9/09 8:49 ON NS NS - 33,408,500 0 43,941,222 0.00 - 762.82 RW1 RW2 RW3 MW7 MW17 PTWA PTWB9/17/09 15:40 ON NS 0 - 33,651,300 242,800 44,184,022 20.35 - 762.82 RW1 RW2 RW3 MW7 MW17 PTWA PTWB9/21/09 11:53 ON NS 0 - 33,742,400 91,100 44,275,122 16.46 - 762.82 RW2 RW3 MW7 MW17 PTWA PTWB(RW-1

Pump Removed to be sent to QED for Service)

9/28/09 7:00 OFF NS NS - 33,807,100 64,700 44,339,822 6.61 - 762.82 Off due to tripped AC breaker9/28/09 10:30 ON NS NS - 33,807,100 0 44,339,822 0.00 - 762.82 RW2 RW3 MW7 MW17 PTWA PTWB9/29/09 8:40 OFF NS NS - 33,834,300 27,200 44,367,022 20.45 - 762.82 Off due to clogged bag filters9/29/09 11:13 ON NS NS - 33,834,300 0 44,367,022 0.00 - 762.82 RW2 RW3 MW7 MW17 PTWA PTWB10/1/09 0:00 ON NS NS - 33,853,483 19,183 44,386,205 8.69 - 762.82 Estimated10/5/09 10:30 ON NS 0 - 34,013,300 159,817 44,546,022 25.01 - 762.82 RW2 RW3 MW7 MW17 PTWA PTWB10/7/09 12:50 ON NS NS - 34,077,500 64,200 44,610,222 21.26 - 762.82 RW2 RW3 MW7 MW17 PTWA PTWB10/12/09 7:01 OFF NS NS - 34,087,800 10,300 44,620,522 1.50 - 762.82 Off Due to ASTHH10/12/09 7:20 ON NS 0 - 34,087,800 0 44,620,522 0.00 - 762.82 RW2 RW3 MW7 MW17 PTWA PTWB10/19/09 12:57 ON NS 0 - 34,327,900 240,100 44,860,622 23.05 - 762.82 RW2 RW3 MW7 MW17 PTWA PTWB10/19/09 15:16 ON NS NS - 34,331,100 3,200 44,863,822 23.02 - 762.82 RW2 RW3 MW7 MW17 PTWA PTWB10/28/09 7:35 ON 512 0 100.0 34,616,800 285,700 45,149,522 22.86 18.41 781.23 RW1 RW2 RW3 MW7 MW17 PTWA PTWB11/2/09 11:23 ON NS 0 - 34,727,300 110,500 45,260,022 14.88 - 781.23 RW1 RW3 MW7 MW17 PTWA PTWB (RW2

Removed because not exhausting)11/9/09 7:30 ON NS 0 - 34,646,300 29,500 45,289,522 3.00 - 781.23 RW1 RW3 MW7 MW17 PTWA PTWB



Date/Time Status (µg/L) (µg/L) (%) (gallons) (gallons) (gallons) (GPM) (gallons) (gallons) Operating Extraction Points




11/9/09 12:00 OFF NS NS - 34,849,900 203,600 45,493,122 754.07 - 781.23 Off for O+M activities(See Field Sheet for Details)

11/9/09 12:33 ON NS NS - 34,849,900 0 45,493,122 0.00 - 781.23 RW1 RW3 MW7 MW17 PTWA PTWB11/10/09 13:00 OFF NS NS - 34,888,600 38,700 45,531,822 26.38 - 781.23 Off On ASTHH11/16/09 10:45 ON NS NS - 34,888,600 0 45,531,822 0.00 - 781.23 RW1 RW3 MW7 MW17 PTWA PTWB11/23/09 8:00 OFF NS NS - 34,975,700 87,100 45,618,922 8.78 - 781.23 Off on ASTHH11/23/09 11:54 ON 510 0 100.0 34,975,700 0 45,618,922 0.00 1.22 782.45 RW1 RW2 RW3 MW7 MW17 PTWA PTWB12/2/09 12:15 OFF NS NS - 35,155,300 179,600 45,798,522 13.84 - 782.45 Off on ASTHH12/4/09 10:45 ON NS 0 - 35,155,300 0 45,798,522 0.00 - 782.45 RW1 RW2 RW3 MW7 MW17 PTWA PTWB12/5/09 23:00 OFF NS NS - 35,216,100 60,800 45,859,322 27.95 - 782.45 OFF on OWSHH12/7/09 8:17 ON NS NS - 35,216,100 0 45,859,322 0.00 - 782.45 RW1 RW2 RW3 MW7 MW17 PTWA PTWB12/7/09 8:41 OFF NS NS - 35,216,700 600 45,859,922 25.00 - 782.45 Off for O+M activities(See Field Sheet for Details)

12/10/09 11:46 ON NS 0 - 35,216,700 0 45,859,922 0.00 - 782.45 RW1 RW2 RW3 MW7 MW17 PTWA PTWB12/15/09 12:54 OFF NS NS - 35,417,000 200,300 46,060,222 27.56 - 782.45 Down on ASTHH will leave off until Friday

12/18/09 (GAC changeout)12/18/09 11:30 ON NS NS - 35,417,000 0 46,060,222 0.00 - 782.45 RW1 RW2 RW3 MW7 MW17 PTWA PTWB12/22/09 8:07 OFF NS NS - 35,454,100 37,100 46,097,322 6.68 - 782.45 Off On OWSHH12/22/09 11:57 ON 1,600 0 100.0 35,454,100 0 46,097,322 0.00 3.36 785.81 RW1 RW2 RW3 MW7 MW17 PTWA PTWB12/23/09 12:02 OFF NS NS - 35,483,300 29,200 46,126,522 20.21 - 785.81 Off On ASTHH12/23/09 12:34 ON NS NS - 35,483,300 0 46,126,522 0.00 - 785.81 RW1 RW2 RW3 MW7 MW17 PTWA PTWB12/28/09 11:29 ON NS 0 - 35,680,400 197,100 46,323,622 27.62 - 785.81 RW1 RW2 RW3 MW7 MW17 PTWA PTWB Notes:(1) Hydrocarbons Recovered Period (gallons) = (avg. inf. conc.) x (e-6) x (1/0.2) x (3.785 L/gal) x (1 lb/453.6 g) x (gallons pumped) x (1 gal/6.26 lbs).

(2) Formula assumes BTEX equals 20% of gasoline.


Benzene Toluene E. Benzene Xylenes BTEX MTBEDate/Time (µg/L) (µg/L) (µg/L) (µg/L) (µg/L) (µg/L)1/5/09 12:40 130 210 18 153 511 2102/2/09 15:25 220 380 38 310 948 3003/2/09 9:45 120 220 19 191 550 2105/11/09 13:05 810 1,300 130 880 3,120 5006/15/09 12:03 240 390 35 310 975 4108/24/09 14:16 1,600 1,900 240 1,050 4,790 67009/9/2009 0900 1,200 1,700 150 1,010 4,060 60010/28/09 10:00 130 200 19 163 512 18011/23/09 14:35 100 200 23 187 510 13012/22/09 13:00 410 600 70 520 1,600 300 Notes:(1) ND: Not Detected above reporting limit.(2) <##: Parameter not detected above the reporting limit.

TABLE A-2: TOTAL FLUIDS EXTRACTION SYSTEM INFLUENT ANALYTICAL RESULTSSEMI-ANNUAL PROGRESS REPORT: JULY THROUGH DECEMBER 2009FORMER CHEVRON FACILITY 122208, 5801 RIGGS ROAD, CHILLUM, MD



Benzene Toluene Ethylbenzene Xylene BTEX MTBEDate/Time (µg/L) (µg/L) (µg/L) (µg/L) (µg/L) (µg/L)1/5/09 12:15 <1 <1 <1 <3 0 <11/12/09 14:35 <1 <1 <1 <3 0 <11/19/09 11:35 <1 <1 <1 <3 0 <11/26/09 12:00 <1 <1 <1 <3 0 1.72/2/09 15:00 <1 <1 <1 <3 0 2.12/9/09 14:25 <1 <1 <1 <3 0 2.12/16/09 17:10 <1 <1 <1 <3 0 2.12/24/09 13:05 <1 <1 <1 <3 0 3.13/2/09 9:20 <1 <1 <1 <3 0 4.63/9/09 11:10 <1 <1 <1 <3 0 4.53/16/09 13:10 <1 <1 <1 <3 0 4.73/23/09 11:40 <1 <1 <1 <3 0 3.85/11/09 13:09 <1 <1 <1 <3 0 8.45/26/09 12:22 <1 <1 <1 <3 0 6.16/3/09 11:37 <1 <1 <1 <3 0 116/8/09 15:27 <1 <1 <1 <3 0 9.66/15/09 0:00 <1 <1 <1 <3 0 9.66/22/09 9:22 <1 <1 <1 <3 0 7.86/29/09 12:02 <1 <1 <1 <3 0 6.97/6/09 0:00 <1 <1 <1 <3 0 7.97/14/09 12:39 <1 <1 <1 <3 0 117/20/09 13:01 <1 <1 <1 <3 0 <17/27/09 12:05 <1 <1 <1 <3 0 <18/3/09 8:01 <1 <1 <1 <3 0 <18/17/09 12:30 <1 <1 <1 <3 0 <18/24/09 14:11 <1 <1 <1 <3 0 <19/2/09 12:15 <1 <1 <1 <3 0 <19/9/2009 0910 <1 <1 <1 <3 0 1.59/17/09 15:50 <1 <1 <1 <3 0 6.59/21/09 12:24 <1 <1 <1 <3 0 8.910/5/09 13:01 <1 <1 <1 <3 0 1810/12/09 7:20 <1 <1 <1 <3 0 1410/19/09 12:58 <1 <1 <1 <3 0 3610/28/09 8:45 <1 <1 <1 <10 0 3311/2/09 11:55 <1 <1 <1 <10 0 3411/9/09 8:45 <1 <1 <1 <10 0 3611/23/2009 14:45:00 <1 <1 <1 <10 0 3912/4/09 12:51 <1 <1 <1 <10 0 6312/10/09 12:15 <1 <1 <1 <10 0 6612/22/09 13:25 <1 <1 <1 <10 0 <112/28/09 13:00 <1 <1 <1 <10 0 <1 Notes:(1) ND: Not Detected above reporting limit.(2) <##: Parameter not detected above the reporting limit.

TABLE A-3: TOTAL FLUIDS EXTRACTION SYSTEM EFFLUENT ANALYTICAL RESULTSSEMI-ANNUAL PROGRESS REPORT: JULY THROUGH DECEMBER 2009FORMER CHEVRON FACILITY 122208, 5801 RIGGS ROAD, CHILLUM, MD



APPENDIX B

DUAL-PHASE EXTRACTION SYSTEM – SOIL VAPOR EXTRACTION DATA

APPENDIX B

DUAL-PHASE EXTRACTION SYSTEM – SOIL VAPOR EXTRACTION DATA

DESCRIPTION OF DATA TABLES

Overview Chevron uses a central database to store remediation system data and laboratory analytical data. The tabulated data in Tables B-1, B-2 and B-3 is an exported summary of soil vapor extraction (“SVE”) system data from the database. These data were recorded by the field technician during site visits. Analytical data for influent samples collected for laboratory analysis are included in Table B-2 to calculate the mass recovery rates of total petroleum hydrocarbons and benzene. Effluent sample data are included in Table B-3 for comparison with permit limits.

The data tables include all system data collected since January 1, 2009. Data collected prior to this date are available in previous progress reports.

The following table lists the column headings in the table with a brief description of each. Please refer to the Process and Instrumentation Diagram (Appendix A) for a schematic of equipment and sample ports.

Column Heading Description Date / Time Date and time data were recorded. System Status System ON or OFF when technician recorded the data. Hour Meter (hours) Field measurement of the hour meter. Manifold Vacuum (in Hg) Field measurement of vacuum in manifold. Influent (ppmv) Field measurement of vapor concentration prior to

treatment using a photoionization detector. Influent (cfm) Field measurement of total vapor flow in manifold. Effluent (ppmv) Field measurement of vapor concentration after treatment

using a photoionization detector. Treatment Efficiency (%) Equation: (Influent-Effluent) / (Influent). Hydrocarbons Recovered (lbs/day) 1

Equation: [(Influent) / (10-6)] * [Manifold Extraction-Flow Rate] * CV1

Hydrocarbons Recovered Period (gal)

Equation: [(Avg. Influent) x (10-6)] * [Avg. Manifold Extraction-Flow Rate]

Hydrocarbons Recovered Cumulative (gal)

Equation: (Avg. Influent BTEX) * (1 L / 0.26 gal) * (lb/454x106 µg) * (current Total Gallons Pumped – previous Total Gallons Pumped on last sampling date) * (gal hydrocarbons / 6.48 lbs hydrocarbons) * (0.2 gal BTEX / gal hydrocarbons).

Operating Extraction Points Wells in operation during the reporting period. Notes (1) Assumptions: Hydrocarbon molecular weight is 92 grams/mole; vapor behaves

like an ideal gas; Average (Avg.) Influent (ppmv) and flow rate (Manifold Extraction in the table) are averages between the current and last events. Unit conversion factors (CV) equations are:

CV1 = (92 grams/mole) * (1 mol/24.45 L) * (28.32 L/ft3) * (1440 min/day) * (1 lb/454 grams) = 338 min*lbs/day.

CV2 = (92 grams/mole) * (1 mol/24.45 L) * (28.32 L/ft3) * (Runtime in minutes) * (1 lb/454 grams) = 0.235 min*lbs.

Hour ManifoldSystem Meter Vacuum Influent Influent Effluent Treatment Period Cumul.

Date/Time Status (hours) (in. H2O) (ppmv) (SCFM) (ppmv) Efficiency (lbs/day) (gallons) (gallons) Operating Extraction Points1/5/09 11:25 ON 26,365.1 12 107 132 49.0 54.2 4.8 6.1 3,742.9 RW1 RW2 RW3 MW7 MW17 PTWA PTWB MP71/12/09 14:15 ON 26,536.0 14 175 141 73.0 58.3 8.3 7.3 3,750.2 RW1 RW2 RW3 MW7 MW17 PTWA PTWB MP71/19/09 10:15 ON 26,699.9 14 210 130 89.0 57.6 9.2 9.4 3,759.6 RW1 RW2 RW3 MW7 MW17 PTWA PTWB MP71/26/09 12:05 ON 26,869.6 14 326 142 144.0 55.8 15.6 13.6 3,773.2 RW1 RW2 RW3 MW7 MW17 PTWA PTWB MP72/2/09 7:55 ON 27,033.4 14 241 139 133.0 44.8 11.3 14.4 3,787.6 RW1 RW2 RW3 MW7 MW17 PTWA PTWB MP72/9/09 8:20 OFF 27,202.3 - - - - - - - 3,787.6 Off to repair well vault plumbing2/9/09 10:20 ON 27,202.3 14 109 144 49.0 55.0 5.3 9.2 3,796.8 RW1 RW2 RW3 MW7 MW17 PTWB MP72/16/09 10:10 OFF 27,371.6 - - - - - - - 3,796.8 Off for routine maintenance2/16/09 16:10 ON 27,371.6 14 137 128 75.0 45.3 5.9 6.2 3,803.1 RW1 RW2 RW3 MW7 MW17 PTWA PTWB MP72/23/09 18:22 OFF 27,540.1 - - - - - - - 3,803.1 Low pressure air compressor - tripped motor starter

2/24/09 10:45 ON 27,540.1 14 136 133 62.0 54.4 6.1 6.6 3,809.7 RW1 RW2 RW3 MW7 MW17 PTWA PTWB MP73/2/09 8:55 ON 27,682.3 14 375 135 162.0 56.8 17.1 10.7 3,820.4 RW1 RW2 RW3 MW7 MW17 PTWA PTWB MP73/4/09 6:45 OFF 27,728.5 - - - - - - - 3,820.4 Low pressure air compressor - tripped motor starter

3/5/09 12:50 ON 27,728.5 14 123 133 64.0 48.0 5.5 3.4 3,823.8 RW1 RW2 RW3 MW7 MW17 PTWA PTWB MP73/9/09 10:30 ON 27,821.2 14 108 133 55.0 49.1 4.9 3.1 3,827.0 RW1 RW2 RW3 MW7 MW17 PTWA PTWB MP73/12/09 11:20 OFF 27,894.4 - - - - - - - 3,827.0 Off on OWS-HH3/12/09 15:50 ON 27,894.4 15 124 131 66.0 46.8 5.5 2.5 3,829.4 RW1 RW2 RW3 MW7 MW17 PTWA PTWB MP73/16/09 8:25 OFF 27,982.7 - - - - - - - 3,829.4 Off to clean air stripper3/16/09 13:00 ON 27,982.7 - - - - - - - 3,829.4 RW1 RW2 RW3 MW7 MW17 PTWA PTWB MP73/16/09 13:30 OFF 27,984.1 - - - - - - - 3,829.4 Off on AST_HH (clogged bag filters)3/16/09 14:04 ON 27,984.1 14 - 129 - - - - 3,829.4 RW1 RW2 RW3 MW7 MW17 PTWA PTWB MP73/19/09 15:40 OFF 28,058.4 - - - - - - - 3,829.4 Off on AST-HH (clogged bag filters)3/23/09 10:52 ON 28,058.4 14 118 134 60.0 49.2 5.3 2.5 3,832.0 RW1 RW2 RW3 MW7 MW17 PTWA PTWB MP73/24/09 8:30 OFF 28,074.7 - - - - - - - 3,832.0 Off on Comp_Lo - Compressor Needs to be

Replaced5/5/09 12:18 ON 28,074.7 14 370 139 272.0 26.5 17.4 1.2 3,833.2 RW1 RW2 RW3 MW7 MW17 PTWA PTWB MP75/11/09 7:00 OFF 28,141.5 - - - - - - - 3,833.2 Off on Comp_Lo - Auto drain on compressor

Replaced5/11/09 12:30 ON 28,141.5 14 32 138 16.9 46.9 1.5 4.1 3,837.3 RW1 RW2 RW3 MW7 MW17 PTWA PTWB MP75/18/09 9:30 OFF 28,311.2 - - - - - - - 3,837.3 Off on Comp_Lo5/18/09 15:18 ON 28,311.2 - - - - - - - 3,837.3 RW1 RW2 RW3 MW7 MW17 PTWA PTWB MP7

(readings not taken)5/20/09 10:28 OFF 28,329.5 - - - - - - - 3,837.3 Off for plumbing repairs to OWS pump 5/20/09 14:42 ON 28,329.5 14 - 149 - - - - 3,837.3 RW1 RW2 RW3 MW7 MW17 PTWA PTWB

MP7(Concentration readings out of range for FID)

5/26/09 7:30 OFF 28,342.1 - - - - - - - 3,837.3 Off on VFD High AMP fault5/26/09 8:02 ON 28,342.1 13 2,250 152 2,000.0 11.1 115.6 9.4 3,846.7 RW1 RW2 RW3 MW7 MW17 PTWA PTWB MP7


TABLE B-1: SOIL VAPOR EXTRACTION SYSTEM DATASEMI-ANNUAL PROGRESS REPORT: JULY THROUGH DECEMBER 2009FORMER CHEVRON FACILITY 122208, 5801 RIGGS ROAD, CHILLUM, MD


APP_ B_122208_4Q09_SVE 011110.xls Page 1 of 3 Printed on: 1/14/2010


Date/Time Status (hours) (in. H2O) (ppmv) (SCFM) (ppmv) Efficiency (lbs/day) (gallons) (gallons) Operating Extraction Points




6/3/09 9:00 OFF 28,371.9 - - - - - - - 3,846.7 Off on VFD High AMP fault6/3/09 11:03 ON 28,371.9 12 2,320 157 2,050.0 11.6 123.1 23.2 3,869.9 RW1 RW2 RW3 MW7 MW17 PTWA PTWB MP76/8/09 7:00 OFF 28,380.7 - - - - - - - 3,869.9 Off on VFD High AMP fault6/8/09 13:12 ON 28,380.7 - - - - - - - 3,869.9 RW1 RW2 RW3 MW7 MW17 PTWA PTWB MP76/8/09 14:22 OFF 28,385.4 - - - - - - - 3,869.9 Off on VFD High AMP fault6/15/09 12:07 OFF 28,552.3 - - - - - - - 3,869.9 Off on VFD High AMP fault (Still counting hours

because CATOX will not Turn Off)6/22/09 7:20 ON 28,552.3 - - - - - - - 3,869.9 RW1 RW2 RW3 MW7 MW17 PTWA PTWB MP7

(on to troubleshoot blower)6/22/09 7:20 OFF 28,723.0 - - - - - - - 3,869.9 Off on VFD High AMP fault (Off time is an estimate)

6/29/09 10:45 OFF 28,723.0 - - - - - - - 3,869.9 Off on VFD High AMP fault (Off time is an estimate)

7/6/09 7:00 OFF 28,886.8 - - - - - - - 3,869.9 Off on VFD High AMP fault (Off time is an estimate)

7/14/09 11:41 OFF 29,083.1 - - - - - - - 3,869.9 Off on VFD High AMP fault, while system was off Catox Hour Meter was still counting. Hour Meter power cut at 1150 on 7/14/09

8/3/09 7:41 OFF 29,083.1 - - - - - - - 3,869.9 Off on VFD High AMP fault 8/3/09 9:48 ON 29,083.1 - - - - - - - 3,869.9 On temporarily to troubleshoot blower motor8/3/09 11:53 OFF 29,085.2 - - - - - - - 3,869.9 Off on VFD High AMP fault 8/17/09 8:18 OFF 29,085.2 - - - - - - - 3,869.9 Off on VFD High AMP fault 8/24/09 10:39 OFF 29,085.2 - - - - - - - 3,869.9 Off on VFD High AMP fault 9/2/09 8:15 OFF 29,085.2 - - - - - - - 3,869.9 Off on VFD High AMP fault 10/7/09 12:00 ON 29,085.2 1 45 130 20.7 54.1 2.0 0.0 3,869.9 RW1 RW2 RW3 MW7 MW17 PTWA PTWB MP7 10/12/09 7:01 OFF 29,100.0 - - - - - - - 3,869.9 Off due to AST HH10/12/09 7:20 ON 29,100.0 12 27 97 9.2 65.3 0.9 0.1 3,870.0 RW1 RW2 RW3 MW7 MW17 PTWA PTWB MP7 10/19/09 12:58 ON 29,275.9 13 1,489 108 1,417.0 4.8 54.4 30.2 3,900.2 RW1 RW2 RW3 MW7 MW17 PTWA PTWB MP7 10/19/09 15:16 ON 29,276.2 - - - - - - - 3,900.2 RW1 RW2 RW3 MW7 MW17 PTWA PTWB MP7 10/28/09 7:35 ON 29,485.6 - - - - - - - 3,900.2 RW1 RW2 RW3 MW7 MW17 PTWA PTWB MP7

(Readings Inadvertently not Recorded)11/2/09 11:23 ON 29,609.4 14 56 98 26.9 52.0 1.9 1.5 3,901.7 RW1 RW2 RW3 MW7 MW17 PTWA PTWB MP7 11/5/09 7:30 OFF 29,653.3 - - - - - - - 3,901.7 Off on VFD High AMP fault 11/5/09 13:57 ON 29,653.3 14 - - - - - - 3,901.7 On temporarily to troubleshoot 11/5/09 14:39 OFF 29,654.0 - - - - - - - 3,901.7 Off on VFD High AMP fault 11/9/09 12:40 ON 29,654.0 10 69 96 35.1 48.9 2.2 0.0 3,901.7 RW1 RW3 MW7 MW17 PTWA PTWB MP7 (RW2

Removed from well to repair)11/10/09 13:00 OFF 29,679.2 - - - - - - - 3,901.7 Off On ASTHH11/16/09 10:45 ON 29,679.2 14 30 109 12.7 57.9 1.1 0.3 3,902.0 RW1 RW3 MW7 MW17 PTWA PTWB MP7 (RW2

Removed from well to repair)11/23/09 0800 OFF 29,751.3 - - - - - - - 3,902.0 Off On ASTHH



Date/Time Status (hours) (in. H2O) (ppmv) (SCFM) (ppmv) Efficiency (lbs/day) (gallons) (gallons) Operating Extraction Points




11/23/09 11:54 ON 29,751.3 14 24 95 11.2 53.5 0.8 0.4 3,902.4 RW1 RW2 RW3 MW7 MW17 PTWA PTWB MP7 12/2/09 12:15 OFF 29,896.1 - - - - - - - 3,902.4 Off On ASTHH12/4/09 10:45 ON 29,896.1 14 700 103 300.0 57.1 24.3 11.4 3,913.8 RW1 RW2 RW3 MW7 MW17 PTWA PTWB MP7

(*FID Readings)12/5/09 23:00 OFF 29,979.3 - - - - - - - 3,913.8 Off On OWSHH12/7/09 8:17 ON 29,979.3 - - - - - - - 3,913.8 RW1 RW2 RW3 MW7 MW17 PTWA PTWB MP7

(System on briefly, readings not taken)12/7/09 8:41 OFF 29,985.5 - - - - - - - 3,913.8 Off for O+M activities(See Field Sheet for Details)

12/10/09 11:46 ON 29,985.5 13 2,343 166 1,729.0 26.2 131.1 5.3 3,919.2 RW1 RW2 RW3 MW7 MW17 PTWA PTWB MP7 (*FID Readings)

12/15/09 12:54 OFF 30,106.2 - - - - - - - 3,919.2 Down on ASTHH will leave off until Friday 12/18/09 (GAC changeout)

12/18/09 11:30 ON 30,106.2 13 250 167 132.0 47.2 14.1 57.4 3,976.5 RW1 RW2 RW3 MW7 MW17 PTWA PTWB MP7 (*FID Readings)

12/22/09 8:07 OFF 30,128.0 - - - - - - - 3,976.5 Off On OWSHH12/22/09 11:57 ON 30,128.0 12 1,024 162 912.0 10.9 55.9 5.0 3,981.5 RW1 RW2 RW3 MW7 MW17 PTWA PTWB MP7

(*FID Readings)12/23/09 12:02 OFF 30,145.2 - - - - - - - 3,981.5 Off On ASTHH12/23/09 12:34 ON 30,145.2 13 - 162 - - - - 3,981.5 RW1 RW2 RW3 MW7 MW17 PTWA PTWB MP712/28/09 11:29 ON 30,264.1 13 2,492 158 1,512.0 39.3 132.7 104.3 4,085.8 RW1 RW2 RW3 MW7 MW17 PTWA PTWB

MP7(Hour Meters Estimated) Notes:(1) Hydrocarbons recovered are expressed as toluene (MW = 92 g/mol @ 77F).(2) Hydrocarbons Recovered (lbs/day) = (inf. conc.) x (92 g/mol) x (mol/24.45 L) x (e-6) x (inf. flow) x (28.32 L/ft3) x (1440 min/day) x (1 lb/453.6 g).(3) Hydrocarbons Recovered Period (gallons) = (avg. inf. conc.) x (92 g/mol) x (mol/24.45 L) x (e-6) x (avg. inf. flow) x (28.32 L/ft3) x (runtime in minutes) x (1 lb/453.6 g) x (gal/6.39 lb).


Benzene Toluene Ethylbenzene Xylene TPH Flow Benzene TPHDate/Time (µg/L) (µg/L) (µg/L) (µg/L) (µg/L) (SCFM) (lbs/hr) (lbs/day)1/5/09 12:10 3.00 13.00 2.00 21.00 1,100 132 0.0015 13.052/2/09 11:45 2.00 14.00 3.00 23.00 1,300 139 0.0010 16.253/2/09 9:55 3.00 15.00 3.00 29.00 1,400 133 0.0015 16.745/11/09 13:45 0.90 4.00 0.80 5.00 620 138 0.0005 7.6910/28/09 9:40 1.60 7.00 1.30 11.00 580 105 0.0006 5.4711/16/09 14:00 0.70 3.10 0.50 3.90 220 109 0.0003 2.1512/22/09 13:20 0.39 1.60 0.30 2.10 260 162 0.0002 3.78 Notes:(1) Benzene (lbs/h) = (benzene conc.) x (e-6) x (1 lb/453.6 g) x (flow) x (28.32 L/ft3) x (60 min/hr).(2) TPH (lbs/day) = (TPH conc.) x (e-6) x (1 lb/453.6 g) x (flow) x (28.32 L/ft3) x (1440 min/day).(3) ug/L = (ppmv) x (MW g/mol) x (mol/24.45 L), where MW benzene = 78 and MW TPH = 92.

Extraction Rate

TABLE B-2: SOIL VAPOR EXTRACTION SYSTEM INFLUENT ANALYTICAL RESULTSSEMI-ANNUAL PROGRESS REPORT: JULY THROUGH DECEMBER 2009FORMER CHEVRON FACILITY 122208, 5801 RIGGS ROAD, CHILLUM, MD



Benzene Toluene Ethylbenzene Xylene TPH Flow Benzene TPHDate/Time (µg/L) (µg/L) (µg/L) (µg/L) (µg/L) (SCFM) (lbs/hr) (lbs/day)1/5/09 12:05 0.8 4 0.6 5 510 131 0.0004 6.032/2/09 11:40 1 5 0.8 6 530 139 0.0005 6.643/2/09 9:50 0.2 2 0.3 3 150 133 0.0001 1.795/11/09 13:40 0.400 2 0.300 2 370 138 0.0002 4.5910/28/09 9:35 0.6 2.4 0.4 3.6 290 105 0.0002 2.7311/16/09 14:05 0.40 1.6 0.3 2.1 170 109 0.0002 1.6612/22/09 13:21 0.16 .66 .12 .84 170 162 0.0001 2.47 Notes:(1) Benzene (lbs/h) = (benzene conc.) x (e-6) x (1 lb/453.6 g) x (flow) x (28.32 L/ft3) x (60 min/hr).(2) TPH (lbs/day) = (TPH conc.) x (e-6) x (1 lb/453.6 g) x (flow) x (28.32 L/ft3) x (1440 min/day).(3) ug/L = (ppmv) x (MW g/mol) x (mol/24.45 L), where MW benzene = 78 and MW TPH = 92.

Discharge Rate

TABLE B-3: SOIL VAPOR EXTRACTION SYSTEM EFFLUENT ANALYTICAL RESULTSSEMI-ANNUAL PROGRESS REPORT: JULY THROUGH DECEMBER 2009FORMER CHEVRON FACILITY 122208, 5801 RIGGS ROAD, CHILLUM, MD



APPENDIX C

GROUNDWATER MONITORING DATA

APPENDIX C

GROUNDWATER MONITORING DATA DESCRIPTION OF DATA TABLE Overview Chevron uses a central database to store groundwater monitoring data including laboratory analytical data. The tabulated data in Appendix C (Table C-1) is an exported summary of groundwater elevation data and analytical data for the period beginning on January 1, 2009, and ending on December 31, 2009 (reporting period plus previous two quarters). Groundwater elevation data were measured using an interface probe in wells near the Service Station and a water level indicator at all other locations. The following table lists the column headings in the table with a brief description of each. Column Heading Description Date Date data were recorded. DTL (ft) Depth to LPH (ft) DTW (ft) Depth to groundwater (ft) LPH Thick. (ft) Equation: (DTW-DTL) GW Elev. (ft) Corrected water table elevation equation:

(TOC) – (DTW) + [(0.75)*(LPH Thickness)] LPH Recovery Liquid Phase Hydrocarbons Recovery Benzene (μg/L) Laboratory reported concentration Toluene (μg/L) Laboratory reported concentration Ethylbenzene (μg/L) Laboratory reported concentration Total Xylenes (μg/L) Laboratory reported concentration MTBE (μg/L) Laboratory reported concentration TPH-GRO (μg/L) Laboratory reported concentration

LPH GW LPHDTL DTW Thick. Elev Recov. BTEX

Date (ft) (ft) (ft) (ft) (gal) (µg/l)

GP-2E(45-50) Screen: 45.0-50.0 ft bgs TOC: 168.17 ft03/18/09 --- 44.38 --- 123.79 No Analytical Results03/30/09 --- 44.27 --- 123.90 ND (2) ND (2) ND (6) ND (2) ND 350.0 (2) 240.0 (100)09/14/09 --- 43.02 --- 125.15 No Analytical Results09/28/09 --- 43.50 --- 124.67 ND (2) ND (2) ND (6) ND (2) ND 450.0 (2) 410.0 (100)

GP-2E(50-55) Screen: 50.0-55.0 ft bgs TOC: 168.27 ft03/18/09 --- 44.49 --- 123.78 No Analytical Results09/14/09 --- 43.14 --- 125.13 No Analytical Results

GP-2E(55-60) Screen: 55.0-60.0 ft bgs TOC: 168.53 ft03/18/09 --- 44.81 --- 123.72 No Analytical Results03/30/09 --- 44.65 --- 123.88 ND (1) ND (1) ND (3) ND (1) ND 130.0 (1) 140.0 (100)09/14/09 --- 43.40 --- 125.13 No Analytical Results09/28/09 --- 43.46 --- 125.07 3.4 (1) ND (1) ND (3) ND (1) 3.4 160.0 (1) 210.0 (100)

GP-2F(45-50) Screen: 45.0-50.0 ft bgs TOC: 159.59 ft03/18/09 --- 45.71 --- 113.88 No Analytical Results03/30/09 --- 45.65 --- 113.94 No Analytical Results03/31/09 ND (1) ND (1) ND (3) ND (1) ND 190.0 (1) 190.0 (100)09/14/09 --- 44.35 --- 115.24 No Analytical Results09/28/09 Obstructed at 43.03

GP-2F(50-55) Screen: 50.0-55.0 ft bgs TOC: 159.59 ft03/18/09 --- 45.43 --- 114.16 No Analytical Results03/30/09 --- 45.41 --- 114.18 3.0 (2) ND (2) ND (6) ND (2) 3.0 380.0 (2) 340.0 (100)09/14/09 Well obstructed09/28/09 --- 44.30 --- 115.29 2.1 (2) ND (2) ND (6) ND (2) 2.1 270.0 (2) 250.0 (100)

GP-7A(20-25) Screen: 20.0-25.0 ft bgs TOC: 158.11 ft03/18/09 --- 20.98 --- 137.13 No Analytical Results

Notes: Abbreviations:1) Reporting limit shown in parenthesis. DTL: Depth to LPH TOC: Top of Casing2) Groundwater elevation corrected for presence of LPH. DTW: Depth to Water ND: Not Detected above reporting limit3) Analytical and LPH Recovery results were rounded. LPH: Liquid Phase Hydrocarbons NA: Not Analyzed4) BTEX summed before rounding. GW Elev: Groundwater Elevation UNK: Unknown

TABLE C-1. GROUNDWATER MONITORING DATASEMI-ANNUAL PROGRESS REPORT: JULY THROUGH DECEMBER 2009

FORMER CHEVRON FACILITY 1222085801 RIGGS ROAD, CHILLUM, MARYLAND

TPH-Ethyl- TotalToluene benzene Xylenes

PERIOD: 1/1/2009 - 12/31/2009

(µg/l) (µg/l)(µg/l) (µg/l) (µg/l) (µg/l)MTBE GROBenzene

APP_C_GW_Mon_4Q09.xls Table 1: Page 1 of 21 Printed On: 1/14/2010






PERIOD: 1/1/2009 - 12/31/2009


GP-7A(20-25) Screen: 20.0-25.0 ft bgs TOC: 158.11 ft03/27/09 --- 20.51 --- 137.60 ND (1) ND (1) ND (3) ND (1) ND 1.3 (1) ND (100)09/14/09 --- 22.02 --- 136.09 No Analytical Results09/29/09 --- 21.18 --- 136.93 ND (1) ND (1) ND (3) ND (1) ND ND (1) ND (100)

GP-7A(25-30) Screen: 25.0-30.0 ft bgs TOC: 158.08 ft03/18/09 --- 20.37 --- 137.71 No Analytical Results09/14/09 --- 18.93 --- 139.15 No Analytical Results

GP-7A(30-35) Screen: 30.0-35.0 ft bgs TOC: 158.09 ft03/18/09 --- 22.58 --- 135.51 No Analytical Results03/27/09 --- 22.58 --- 135.51 1.4 (1) ND (1) ND (3) ND (1) 1.4 1.1 (1) ND (100)09/14/09 --- 22.47 --- 135.62 No Analytical Results09/29/09 --- 21.80 --- 136.29 1.5 (1) ND (1) ND (3) ND (1) 1.5 1.4 (1) ND (100)

GP-7A(35-40) Screen: 35.0-40.0 ft bgs TOC: 158.09 ft03/18/09 --- 23.14 --- 134.95 No Analytical Results03/27/09 --- 22.79 --- 135.30 440.0 (2) 69.0 (2) 55.0 (6) 6.2 (2) 570.2 240.0 (2) 2,200.0 (100)09/14/09 --- 21.44 --- 136.65 No Analytical Results09/29/09 --- 21.57 --- 136.52 170.0 (1) 23.0 (1) 15.7 (3) 1.9 (1) 210.6 210.0 (1) 1,400.0 (100)


GP-9A(20-25) Screen: 20.0-25.0 ft bgs TOC: 158.86 ft03/18/09 --- 18.99 --- 139.87 No Analytical Results03/27/09 --- 19.11 --- 139.75 ND (1) ND (1) ND (3) ND (1) ND ND (1) ND (100)09/14/09 --- 17.80 --- 141.06 No Analytical Results09/29/09 --- 18.23 --- 140.63 ND (1) ND (1) ND (3) ND (1) ND ND (1) ND (100)








PERIOD: 1/1/2009 - 12/31/2009




GP-11A(20-25) Screen: 20.0-25.0 ft bgs TOC: 158.28 ft03/18/09 --- 16.59 --- 141.69 No Analytical Results03/27/09 --- 17.35 --- 140.93 No Analytical Results03/30/09 ND (1) ND (1) ND (3) ND (1) ND ND (1) ND (100)09/14/09 --- 19.68 --- 138.60 No Analytical Results09/29/09 --- 18.48 --- 139.80 ND (1) ND (1) ND (3) ND (1) ND ND (1) ND (100)

GP-11A(25-30) Screen: 25.0-30.0 ft bgs TOC: 158.43 ft03/18/09 Cannot remove well cap09/14/09 --- 19.89 --- 138.54 No Analytical Results



GP-24A Screen: 24.0-44.0 ft bgs TOC: 170.83 ft03/18/09 --- 35.52 --- 135.31 No Analytical Results04/01/09 --- 34.25 --- 136.58 ND (1) 1.3 (1) 12.1 (3) ND (1) 13.4 ND (1) 270.0 (100)09/14/09 --- 32.98 --- 137.85 No Analytical Results09/24/09 --- 32.61 --- 138.22 ND (1) 1.6 (1) 19.1 (3) ND (1) 20.7 ND (1) 350.0 (100)








PERIOD: 1/1/2009 - 12/31/2009


GP-27A Screen: 41.0-51.0 ft bgs TOC: 172.06 ft01/26/09 --- 41.79 --- 130.27 No Analytical Results02/24/09 --- 41.86 --- 130.20 No Analytical Results03/18/09 --- 42.69 --- 129.37 No Analytical Results04/07/09 --- 40.86 --- 131.20 3,400.0 (50) 1,900.0 (50) 11,100.0 (150) 8,400.0 (50) 24,800.0 3,500.0 (50) 67,000.0 (10000)04/27/09 --- 40.97 --- 131.09 No Analytical Results05/27/09 --- 41.21 --- 130.85 No Analytical Results06/15/09 --- 40.97 --- 131.09 No Analytical Results07/27/09 --- 40.42 --- 131.64 No Analytical Results08/24/09 --- 40.38 --- 131.68 No Analytical Results09/14/09 --- 43.42 --- 128.64 No Analytical Results09/23/09 --- 42.39 --- 129.67 3,500.0 (50) 1,700.0 (50) 10,300.0 (150) 8,900.0 (50) 24,400.0 1,500.0 (50) 49,000.0 (20000)10/28/09 --- 41.83 --- 130.23 No Analytical Results11/16/09 --- 41.37 --- 130.69 No Analytical Results12/22/09 Covered by snow

GP-30A Screen: 29.0-49.0 ft bgs TOC: 171.78 ft01/26/09 --- 43.10 --- 128.68 No Analytical Results02/24/09 --- 41.15 --- 130.63 No Analytical Results03/18/09 --- 42.86 --- 128.92 No Analytical Results04/07/09 --- 37.06 --- 134.72 5,200.0 (100) 400.0 (100) 3,800.0 (300) 4,700.0 (100) 14,100.0 22,000.0 (100) 52,000.0 (5000)04/27/09 --- 36.71 --- 135.07 No Analytical Results05/27/09 --- 40.81 --- 130.97 No Analytical Results06/15/09 --- 39.56 --- 132.22 No Analytical Results07/27/09 --- 39.52 --- 132.26 No Analytical Results08/24/09 --- 39.74 --- 132.04 No Analytical Results09/14/09 --- 41.15 --- 130.63 No Analytical Results09/24/09 --- 37.27 --- 134.51 7,400.0 (100) 500.0 (100) 3,800.0 (300) 7,500.0 (100) 19,200.0 15,000.0 (100) 59,000.0 (5000)10/28/09 --- 42.10 --- 129.68 No Analytical Results11/16/09 --- 38.23 --- 133.55 No Analytical Results12/22/09 --- 36.43 --- 135.35 No Analytical Results








PERIOD: 1/1/2009 - 12/31/2009


GP-35A Screen: 25.0-45.0 ft bgs TOC: 171.96 ft01/26/09 --- 43.92 --- 128.04 No Analytical Results02/24/09 --- 38.94 --- 133.02 No Analytical Results03/18/09 --- 43.70 --- 128.26 No Analytical Results04/01/09 --- 35.70 --- 136.26 1,800.0 (20) 250.0 (20) 2,010.0 (60) 3,700.0 (20) 7,760.0 290.0 (20) 16,000.0 (2000)04/27/09 --- 34.65 --- 137.31 No Analytical Results05/27/09 --- 43.17 --- 128.79 No Analytical Results06/15/09 --- 37.15 --- 134.81 No Analytical Results07/27/09 --- 35.51 --- 136.45 No Analytical Results08/24/09 --- 35.36 --- 136.60 No Analytical Results09/14/09 --- 39.56 --- 132.40 No Analytical Results09/24/09 --- 35.83 --- 136.13 2,800.0 (50) 890.0 (50) 5,600.0 (150) 5,800.0 (50) 15,090.0 300.0 (50) 26,000.0 (1000)10/28/09 --- 44.80 --- 127.16 No Analytical Results11/16/09 --- 35.63 --- 136.33 No Analytical Results12/22/09 Covered by snow

GP-38A Screen: 29.0-49.0 ft bgs TOC: 171.22 ft01/26/09 --- 40.99 --- 130.23 No Analytical Results02/24/09 --- 39.40 --- 131.82 No Analytical Results03/18/09 --- 40.16 --- 131.06 No Analytical Results04/07/09 --- 35.11 --- 136.11 44.0 (2) 4.6 (2) 144.0 (6) 6.8 (2) 199.4 ND (2) 4,700.0 (1000)04/27/09 --- 35.00 --- 136.22 No Analytical Results05/27/09 --- 35.55 --- 135.67 No Analytical Results06/15/09 --- 35.16 --- 136.06 No Analytical Results07/27/09 --- 35.09 --- 136.13 No Analytical Results08/24/09 --- 35.25 --- 135.97 No Analytical Results09/14/09 --- 36.07 --- 135.15 No Analytical Results09/24/09 --- 35.28 --- 135.94 2.7 (1) 3.4 (1) 124.0 (3) 1.5 (1) 131.6 ND (1) 3,400.0 (100)10/28/09 --- 39.02 --- 132.20 No Analytical Results11/16/09 --- 34.36 --- 136.86 No Analytical Results12/22/09 --- 35.09 --- 136.13 No Analytical Results








PERIOD: 1/1/2009 - 12/31/2009


GP-39A Screen: 35.0-55.0 ft bgs TOC: 172.46 ft03/18/09 --- 45.29 --- 127.17 No Analytical Results03/31/09 --- 44.32 --- 128.14 2,200.0 (25) 90.0 (25) 820.0 (75) 820.0 (25) 3,930.0 4,900.0 (25) 11,000.0 (2000)09/14/09 Obstructed by sampler at 44.43ft09/23/09 --- 43.98 --- 128.48 3,100.0 (25) 240.0 (25) 1,660.0 (75) 2,200.0 (25) 7,200.0 4,700.0 (25) 15,000.0 (1000)

GP-41A Screen: 32.0-52.0 ft bgs TOC: 172.28 ft03/18/09 --- 43.09 --- 129.19 No Analytical Results03/31/09 --- 42.55 --- 129.73 7.8 (1) ND (1) 11.0 (3) ND (1) 18.8 29.0 (1) 280.0 (200)09/14/09 --- 42.80 --- 129.48 No Analytical Results09/23/09 --- 42.39 --- 129.89 7.3 (1) ND (1) 13.0 (3) ND (1) 20.3 1.7 (1) 160.0 (100)

GP-44A Screen: 26.0-46.0 ft bgs TOC: 176.20 ft03/18/09 --- 31.59 --- 144.61 No Analytical Results04/01/09 --- 31.01 --- 145.19 ND (10) 230.0 (10) 1,430.0 (30) 54.0 (10) 1,714.0 ND (10) 7,700.0 (500)09/14/09 --- 30.69 --- 145.51 No Analytical Results09/24/09 --- 29.66 --- 146.54 ND (2) 110.0 (2) 700.0 (6) 22.0 (2) 832.0 ND (2) 7,700.0 (200)

MP-7 Screen: 35.0-55.0 ft bgs TOC: 172.17 ft01/26/09 --- 39.74 --- 132.43 No Analytical Results02/24/09 --- 39.71 --- 132.46 No Analytical Results03/18/09 --- 42.55 --- 129.66 No Analytical Results04/27/09 --- 41.02 --- 131.15 No Analytical Results05/27/09 --- 40.90 --- 131.32 No Analytical Results06/15/09 --- 41.16 --- 131.01 No Analytical Results07/27/09 --- 40.61 --- 131.56 No Analytical Results08/24/09 --- 40.65 --- 131.52 No Analytical Results09/14/09 43.27 43.83 0.56 128.82 No Analytical Results10/28/09 --- 37.90 --- 134.27 No Analytical Results11/16/09 --- 37.92 --- 134.25 No Analytical Results12/22/09 Covered by snow








PERIOD: 1/1/2009 - 12/31/2009


MP-20 Screen: 40.0-55.0 ft bgs TOC: 172.16 ft03/18/09 --- 44.00 --- 128.16 No Analytical Results09/14/09 --- 43.79 --- 128.37 No Analytical Results



MW-1 Screen: 20.0-35.0 ft bgs TOC: 170.46 ft03/18/09 --- 34.99 --- 135.47 No Analytical Results09/14/09 --- 32.42 --- 138.04 No Analytical Results

MW-2 Screen: 20.0-35.0 ft bgs TOC: 171.41 ft03/18/09 Dry09/14/09 --- 32.72 --- 138.69 No Analytical Results



MW-5 Screen: 20.0-35.0 ft bgs TOC: 172.31 ft03/18/09 Dry04/01/09 --- 32.46 --- 139.85 ND (1) ND (1) ND (3) ND (1) ND ND (1) ND (100)








PERIOD: 1/1/2009 - 12/31/2009


MW-5 Screen: 20.0-35.0 ft bgs TOC: 172.31 ft09/14/09 Dry09/24/09 DRY

MW-6 Screen: 30.0-45.0 ft bgs TOC: 171.12 ft03/18/09 --- 35.91 --- 135.21 No Analytical Results04/01/09 --- 34.25 --- 136.87 No Analytical Results04/02/09 3.5 (2) 100.0 (2) 166.0 (6) 12.0 (2) 281.5 ND (2) 2,300.0 (100)09/14/09 --- 34.17 --- 136.95 No Analytical Results09/24/09 --- 33.30 --- 137.82 2.0 (1) 50.0 (1) 100.0 (3) 5.1 (1) 157.1 ND (1) 890.0 (100)

MW-7 Screen: 20.0-68.0 ft bgs TOC: 177.11 ft01/26/09 --- 57.20 --- 119.91 No Analytical Results02/24/09 --- 57.20 --- 119.91 No Analytical Results03/18/09 --- 52.92 --- 124.19 No Analytical Results04/01/09 --- 43.71 --- 133.40 3,400.0 (25) 670.0 (25) 2,770.0 (75) 5,300.0 (25) 12,140.0 1,300.0 (25) 23,000.0 (5000)04/27/09 --- 42.04 --- 135.07 No Analytical Results05/27/09 --- 48.50 --- 128.61 No Analytical Results06/15/09 --- 43.35 --- 133.76 No Analytical Results09/14/09 --- 49.44 --- 127.67 No Analytical Results09/29/09 System 550.0 (5) 72.0 (5) 430.0 (15) 640.0 (5) 1,692.0 270.0 (5) 3,300.0 (200)10/28/09 --- 35.00 --- 142.11 No Analytical Results11/16/09 --- 37.96 --- 139.15 No Analytical Results12/22/09 --- 41.38 --- 135.73 No Analytical Results










PERIOD: 1/1/2009 - 12/31/2009


MW-15 Screen: 10.0-50.0 ft bgs TOC: 172.34 ft03/18/09 --- 31.11 --- 141.23 No Analytical Results04/01/09 --- 30.80 --- 141.54 10.0 (1) 16.0 (1) 57.0 (3) 38.0 (1) 121.0 ND (1) 830.0 (100)09/14/09 --- 30.58 --- 141.76 No Analytical Results09/24/09 --- 30.55 --- 141.79 7.0 (1) ND (1) ND (3) ND (1) 7.0 ND (1) ND (100)

MW-16 Screen: UNK TOC: 171.05 ft01/26/09 --- 40.30 --- 130.75 No Analytical Results02/24/09 Dry03/18/09 --- 39.89 --- 131.16 No Analytical Results03/30/09 --- 39.03 --- 132.02 27.0 (2) ND (2) ND (6) 6.4 (2) 33.4 480.0 (2) 490.0 (100)04/27/09 --- 37.56 --- 133.49 No Analytical Results05/27/09 --- 37.28 --- 133.77 No Analytical Results06/15/09 --- 37.95 --- 133.10 No Analytical Results07/27/09 --- 38.09 --- 132.96 No Analytical Results08/24/09 --- 37.52 --- 133.53 No Analytical Results09/14/09 --- 37.04 --- 134.01 No Analytical Results09/28/09 --- 37.21 --- 133.84 27.0 (1) 2.9 (1) 38.0 (3) 20.0 (1) 87.9 6.0 (1) 350.0 (100)10/28/09 --- 39.48 --- 131.57 No Analytical Results11/16/09 --- 37.83 --- 133.22 No Analytical Results12/22/09 --- 36.93 --- 134.12 No Analytical Results

MW-17 Screen: 30.0-50.0 ft bgs TOC: 170.67 ft03/18/09 --- 45.29 --- 125.38 No Analytical Results04/07/09 --- 38.16 --- 132.51 5,600.0 (50) 1,600.0 (50) 7,700.0 (150) 10,000.0 (50) 24,900.0 6,000.0 (50) 40,000.0 (10000)09/14/09 --- 44.90 --- 125.77 No Analytical Results09/29/09 System 4,400.0 (50) 820.0 (50) 5,300.0 (150) 8,300.0 (50) 18,820.0 6,200.0 (50) 31,000.0 (1000)









PERIOD: 1/1/2009 - 12/31/2009


MW-18 Screen: 29.0-44.0 ft bgs TOC: 168.45 ft03/18/09 --- 34.02 --- 134.43 No Analytical Results03/30/09 --- 33.07 --- 135.38 14.0 (20) 380.0 (20) 5,000.0 (60) 810.0 (20) 6,204.0 ND (20) 30,000.0 (5000)04/27/09 --- 32.42 --- 136.03 No Analytical Results05/27/09 --- 31.30 --- 137.15 No Analytical Results06/15/09 --- 30.57 --- 137.88 No Analytical Results07/27/09 --- 30.12 --- 138.33 No Analytical Results08/24/09 --- 30.45 --- 138.00 No Analytical Results09/14/09 --- 16.74 --- 151.71 No Analytical Results09/28/09 --- 31.17 --- 137.28 ND (20) 19.0 (20) 3,500.0 (60) 140.0 (20) 3,659.0 ND (20) 26,000.0 (2000)10/28/09 --- 32.02 --- 136.43 No Analytical Results11/16/09 --- 31.61 --- 136.84 No Analytical Results12/22/09 Covered by snow

MW-19 Screen: 30.0-45.0 ft bgs TOC: 169.56 ft03/18/09 --- 37.98 --- 131.58 No Analytical Results03/30/09 --- 37.22 --- 132.34 ND (1) ND (1) ND (3) ND (1) ND ND (1) ND (100)09/14/09 --- 33.89 --- 135.67 No Analytical Results09/28/09 --- 35.48 --- 134.08 ND (1) ND (1) ND (3) ND (1) ND ND (1) ND (100)

MW-20 Screen: 30.0-50.0 ft bgs TOC: 176.27 ft03/18/09 --- 38.19 --- 138.08 No Analytical Results04/02/09 --- 38.10 --- 138.17 2.3 (1) ND (1) ND (3) ND (1) 2.3 ND (1) 250.0 (100)09/14/09 --- 37.49 --- 138.78 No Analytical Results09/24/09 --- 37.41 --- 138.86 1.7 (1) ND (1) ND (3) ND (1) 1.7 ND (1) 300.0 (100)

MW-21 Screen: 28.0-48.0 ft bgs TOC: 173.37 ft03/18/09 --- 36.97 --- 136.39 No Analytical Results04/02/09 --- 36.20 --- 137.17 10.0 (1) ND (1) 8.7 (3) ND (1) 18.7 17.0 (1) 260.0 (100)09/14/09 --- 36.31 --- 137.05 No Analytical Results09/24/09 --- 36.04 --- 137.33 9.1 (1) ND (1) 8.6 (3) ND (1) 17.7 ND (1) 230.0 (100)








PERIOD: 1/1/2009 - 12/31/2009


MW-22 Screen: 31.5-51.5 ft bgs TOC: 171.23 ft01/26/09 --- 42.15 --- 129.08 No Analytical Results02/24/09 --- 41.58 --- 129.65 No Analytical Results03/18/09 --- 42.15 --- 129.08 No Analytical Results03/30/09 --- 39.48 --- 131.75 5,900.0 (100) 1,500.0 (100) 10,100.0 (300) 16,000.0 (100) 33,500.0 680.0 (100) 55,000.0 (10000)04/27/09 --- 38.72 --- 132.51 No Analytical Results05/27/09 --- 39.76 --- 131.47 No Analytical Results06/15/09 --- 39.45 --- 131.78 No Analytical Results07/27/09 --- 39.07 --- 132.16 No Analytical Results08/24/09 --- 39.05 --- 132.18 No Analytical Results09/14/09 Obstructed by Hydrasleeve sampler09/28/09 --- 38.19 --- 133.04 4,200.0 (100) 960.0 (100) 9,300.0 (300) 9,600.0 (100) 24,060.0 420.0 (100) 55,000.0 (2000)10/28/09 --- 43.26 --- 127.97 No Analytical Results11/16/09 --- 39.46 --- 131.77 No Analytical Results12/22/09 --- 38.94 --- 132.29 No Analytical Results

MW-23 Screen: 32.0-52.0 ft bgs TOC: 171.31 ft03/18/09 --- 44.34 --- 126.96 No Analytical Results03/30/09 --- 43.53 --- 127.78 2.3 (1) ND (1) ND (3) ND (1) 2.3 6.8 (1) ND (100)09/14/09 --- 43.57 --- 127.73 No Analytical Results09/28/09 --- 42.50 --- 128.81 9.6 (1) ND (1) ND (3) ND (1) 9.6 24.0 (1) ND (100)

MW-24A Screen: 16.0-23.5 ft bgs TOC: 157.38 ft01/26/09 --- 21.67 --- 135.71 No Analytical Results02/24/09 --- 22.81 --- 134.57 No Analytical Results03/18/09 --- 21.04 --- 136.34 No Analytical Results03/27/09 --- 21.83 --- 135.55 8.3 (20) 610.0 (20) 3,290.0 (60) 52.0 (20) 3,960.3 ND (20) 46,000.0 (2500)04/27/09 --- 20.34 --- 137.04 No Analytical Results05/27/09 --- 19.94 --- 137.44 No Analytical Results06/15/09 --- 18.97 --- 138.41 No Analytical Results07/27/09 --- 19.39 --- 137.99 No Analytical Results08/24/09 --- 19.76 --- 137.62 No Analytical Results








PERIOD: 1/1/2009 - 12/31/2009


MW-24A Screen: 16.0-23.5 ft bgs TOC: 157.38 ft09/14/09 Obstructed by Hydrasleeve sampler09/29/09 --- 20.48 --- 136.90 ND (5) 250.0 (5) 1,750.0 (15) 23.0 (5) 2,023.0 ND (5) 14,000.0 (2000)10/28/09 --- 20.92 --- 136.46 No Analytical Results11/16/09 --- 20.50 --- 136.88 No Analytical Results12/22/09 Covered by snow

MW-24B Screen: 22.5-30.0 ft bgs TOC: 157.45 ft03/18/09 --- 22.07 --- 135.38 No Analytical Results03/27/09 --- 21.91 --- 135.54 17.0 (20) 290.0 (20) 2,150.0 (60) 190.0 (20) 2,647.0 ND (20) 12,000.0 (2500)09/14/09 --- 20.29 --- 137.16 No Analytical Results09/29/09 --- 20.52 --- 136.93 ND (5) 20.0 (5) 890.0 (15) 6.8 (5) 916.8 ND (5) 12,000.0 (500)

MW-25A Screen: 22.0-29.5 ft bgs TOC: 149.99 ft03/18/09 --- 26.96 --- 123.03 No Analytical Results03/27/09 --- 27.01 --- 122.98 No Analytical Results03/30/09 ND (1) ND (1) ND (3) ND (1) ND ND (1) ND (100)09/14/09 Obstructed by Hydrasleeve sampler09/22/09 --- 26.64 --- 123.35 ND (1) ND (1) ND (3) ND (1) ND 2.5 (1) ND (100)

MW-25B Screen: 45.0-55.0 ft bgs TOC: 150.95 ft03/18/09 --- 27.36 --- 123.58 No Analytical Results03/27/09 --- 27.72 --- 123.23 450.0 (2) ND (2) 83.0 (6) ND (2) 533.0 410.0 (2) 1,800.0 (100)09/14/09 Obstructed by Hydrasleeve sampler09/22/09 --- 26.15 --- 124.80 170.0 (2) ND (2) 29.0 (6) ND (2) 199.0 260.0 (2) 820.0 (200)

MW-26A Screen: 2.0-9.5 ft bgs TOC: 135.62 ft03/18/09 --- 4.91 --- 130.70 No Analytical Results03/25/09 --- 4.97 --- 130.65 ND (1) ND (1) ND (3) ND (1) ND ND (1) ND (100)09/14/09 --- 4.80 --- 130.81 No Analytical Results09/22/09 --- 4.94 --- 130.68 ND (1) ND (1) ND (3) ND (1) ND ND (1) ND (100)








PERIOD: 1/1/2009 - 12/31/2009


MW-26B Screen: 21.5-26.5 ft bgs TOC: 135.74 ft03/18/09 --- 6.44 --- 129.30 No Analytical Results03/25/09 --- 6.46 --- 129.28 130.0 (1) ND (1) 8.5 (3) ND (1) 138.5 230.0 (1) 430.0 (100)09/14/09 --- 6.02 --- 129.72 No Analytical Results09/22/09 --- 6.00 --- 129.74 150.0 (1) ND (1) 9.1 (3) ND (1) 159.1 200.0 (1) 570.0 (100)

MW-27A Screen: 8.0-15.5 ft bgs TOC: 128.92 ft03/18/09 --- 11.22 --- 117.69 No Analytical Results03/25/09 --- 11.27 --- 117.65 ND (1) ND (1) ND (3) ND (1) ND 32.0 (1) ND (100)09/14/09 --- 10.16 --- 118.75 No Analytical Results09/21/09 --- 10.24 --- 118.68 ND (1) ND (1) ND (3) ND (1) ND 12.0 (1) ND (100)

MW-27B Screen: 30.5-40.5 ft bgs TOC: 128.92 ft03/18/09 --- 13.56 --- 115.35 No Analytical Results03/25/09 --- 13.60 --- 115.32 19.0 (1) ND (1) 3.1 (3) ND (1) 22.1 240.0 (1) 280.0 (100)09/14/09 --- 12.69 --- 116.22 No Analytical Results09/22/09 --- 12.73 --- 116.19 6.5 (1) ND (1) ND (3) ND (1) 6.5 160.0 (1) 250.0 (100)


MW-28B Screen: 15.5-25.5 ft bgs TOC: 125.49 ft03/18/09 --- 4.71 --- 120.78 No Analytical Results03/23/09 --- 4.70 --- 120.79 ND (1) ND (1) ND (3) ND (1) ND ND (1) ND (100)09/14/09 --- 4.23 --- 121.26 No Analytical Results09/21/09 --- 4.32 --- 121.17 ND (1) ND (1) ND (3) ND (1) ND ND (1) ND (100)

MW-29A Screen: 5.0-12.5 ft bgs TOC: 115.70 ft03/18/09 --- 8.00 --- 107.69 No Analytical Results








PERIOD: 1/1/2009 - 12/31/2009


MW-29A Screen: 5.0-12.5 ft bgs TOC: 115.70 ft03/23/09 --- 8.07 --- 107.63 ND (1) ND (1) ND (3) ND (1) ND 7.4 (1) ND (100)09/14/09 --- 7.23 --- 108.46 No Analytical Results09/21/09 --- 7.22 --- 108.48 ND (1) ND (1) ND (3) ND (1) ND 9.7 (1) ND (100)

MW-29B Screen: 19.0-29.0 ft bgs TOC: 115.54 ft03/18/09 --- 6.83 --- 108.70 No Analytical Results03/23/09 --- 6.97 --- 108.57 ND (1) ND (1) ND (3) ND (1) ND 72.0 (1) ND (100)09/14/09 --- 6.79 --- 108.74 No Analytical Results09/21/09 --- 6.03 --- 109.51 ND (1) ND (1) ND (3) ND (1) ND 58.0 (1) 150.0 (100)


MW-31A Screen: 4.0-11.5 ft bgs TOC: 135.19 ft03/18/09 --- 6.04 --- 129.15 No Analytical Results09/14/09 --- 5.72 --- 129.47 No Analytical Results

MW-31B Screen: 11.5-21.5 ft bgs TOC: 135.81 ft03/18/09 --- 5.69 --- 130.12 No Analytical Results03/24/09 --- 5.60 --- 130.21 ND (1) ND (1) ND (3) ND (1) ND ND (1) ND (100)09/14/09 --- 5.25 --- 130.56 No Analytical Results09/21/09 --- 5.38 --- 130.43 ND (1) ND (1) ND (3) ND (1) ND ND (1) ND (100)









PERIOD: 1/1/2009 - 12/31/2009



MW-33B Screen: 13.0-23.0 ft bgs TOC: 126.16 ft03/18/09 --- 4.89 --- 121.27 No Analytical Results03/24/09 --- 4.92 --- 121.24 380.0 (2) ND (2) 13.0 (6) ND (2) 393.0 220.0 (2) 950.0 (100)09/14/09 --- 4.49 --- 121.67 No Analytical Results09/21/09 --- 3.54 --- 122.62 380.0 (2) ND (2) 11.4 (6) ND (2) 391.4 240.0 (2) 1,100.0 (200)

MW-33C Screen: 23.0-33.0 ft bgs TOC: 125.84 ft03/18/09 --- 4.87 --- 120.96 No Analytical Results03/24/09 --- 4.94 --- 120.90 4.4 (1) ND (1) ND (3) ND (1) 4.4 26.0 (1) ND (100)09/14/09 --- 4.39 --- 121.44 No Analytical Results09/21/09 --- 4.50 --- 121.34 8.4 (1) ND (1) ND (3) ND (1) 8.4 24.0 (1) ND (100)

MW-33S Screen: 2.0-7.0 ft bgs TOC: 126.58 ft03/18/09 --- 3.83 --- 122.74 No Analytical Results03/24/09 --- 3.96 --- 122.62 ND (1) ND (1) ND (3) ND (1) ND ND (1) ND (100)09/14/09 --- 3.30 --- 123.27 No Analytical Results09/21/09 --- 3.63 --- 122.95 ND (1) ND (1) ND (3) ND (1) ND ND (1) ND (100)

MW-34A Screen: 7.0-14.5 ft bgs TOC: 107.41 ft03/18/09 --- 8.99 --- 98.42 No Analytical Results09/14/09 --- 9.05 --- 98.36 No Analytical Results

MW-34B Screen: 14.5-24.5 ft bgs TOC: 107.40 ft03/18/09 --- 9.29 --- 98.11 No Analytical Results09/14/09 --- 9.28 --- 98.12 No Analytical Results








PERIOD: 1/1/2009 - 12/31/2009


MW-37 Screen: 8.0-15.5 ft bgs TOC: 152.61 ft03/18/09 Dry09/14/09 --- 15.13 --- 137.48 No Analytical Results

MW-38 Screen: 8.0-15.5 ft bgs TOC: 146.91 ft03/18/09 --- 11.04 --- 135.86 No Analytical Results03/27/09 --- 11.02 --- 135.89 ND (1) ND (1) ND (3) ND (1) ND ND (1) ND (100)09/14/09 --- 10.37 --- 136.53 No Analytical Results09/22/09 --- 10.45 --- 136.46 No Analytical Results09/23/09 ND (1) ND (1) ND (3) ND (1) ND ND (1) ND (100)

MW-39 Screen: 6.0-13.5 ft bgs TOC: 146.01 ft03/18/09 Dry09/14/09 Dry

MW-39R Screen: 13.0-20.5 ft bgs TOC: 146.01 ft03/18/09 --- 17.31 --- 128.70 No Analytical Results03/27/09 --- 17.32 --- 128.69 ND (1) ND (1) ND (3) ND (1) ND ND (1) ND (100)09/14/09 --- 16.65 --- 129.36 No Analytical Results09/22/09 --- 16.81 --- 129.20 ND (1) ND (1) ND (3) ND (1) ND ND (1) ND (100)

MW-40 Screen: 20.0-27.5 ft bgs TOC: 145.18 ft03/18/09 --- 23.38 --- 121.79 No Analytical Results03/27/09 --- 23.36 --- 121.82 ND (1) ND (1) ND (3) ND (1) ND 1.9 (1) ND (100)09/14/09 --- 21.63 --- 123.54 No Analytical Results09/22/09 --- 32.28 --- 112.90 ND (1) ND (1) ND (3) ND (1) ND ND (1) ND (100)









PERIOD: 1/1/2009 - 12/31/2009


MW-41B Screen: 28.0-38.0 ft bgs TOC: 136.82 ft03/18/09 --- 20.53 --- 116.29 No Analytical Results03/25/09 --- 20.59 --- 116.23 ND (1) ND (1) ND (3) ND (1) ND 16.0 (1) ND (100)09/14/09 --- 19.13 --- 117.69 No Analytical Results09/22/09 --- 19.22 --- 117.60 ND (1) ND (1) ND (3) ND (1) ND 13.0 (1) ND (100)

MW-42 Screen: 2.0-9.5 ft bgs TOC: 140.03 ft03/18/09 --- 8.67 --- 131.35 No Analytical Results03/25/09 --- 8.48 --- 131.55 ND (1) ND (1) ND (3) ND (1) ND ND (1) ND (100)09/14/09 Obstructed by Hydrasleeve sampler09/22/09 --- 7.96 --- 132.07 ND (1) ND (1) ND (3) ND (1) ND ND (1) ND (100)


MW-43B Screen: 21.0-31.0 ft bgs TOC: 134.09 ft03/18/09 --- 9.53 --- 124.56 No Analytical Results03/25/09 --- 9.43 --- 124.66 4.3 (1) ND (1) ND (3) ND (1) 4.3 17.0 (1) ND (100)09/14/09 --- 8.58 --- 125.51 No Analytical Results09/22/09 --- 8.68 --- 125.41 2.6 (1) ND (1) ND (3) ND (1) 2.6 11.0 (1) ND (100)









PERIOD: 1/1/2009 - 12/31/2009


MW-44B Screen: 29.0-39.0 ft bgs TOC: 130.24 ft03/18/09 --- 12.49 --- 117.75 No Analytical Results03/25/09 --- 10.18 --- 120.06 ND (1) ND (1) ND (3) ND (1) ND 94.0 (1) 100.0 (100)09/14/09 --- 11.62 --- 118.62 No Analytical Results09/21/09 --- 11.67 --- 118.57 ND (1) ND (1) ND (3) ND (1) ND 76.0 (1) 120.0 (100)

MW-45 Screen: 35.0-55.0 ft bgs TOC: 173.89 ft03/18/09 --- 44.80 --- 129.09 No Analytical Results03/31/09 --- 43.02 --- 130.87 21.0 (1) ND (1) 29.5 (3) 2.7 (1) 53.2 ND (1) 740.0 (500)09/14/09 --- 43.91 --- 129.98 No Analytical Results09/23/09 --- 47.67 --- 126.22 130.0 (1) 1.2 (1) 103.0 (3) 6.5 (1) 240.7 ND (1) 920.0 (100)

MW-46 Screen: 38.0-58.0 ft bgs TOC: 174.12 ft03/18/09 --- 48.12 --- 125.99 No Analytical Results03/31/09 --- 47.63 --- 126.49 ND (1) ND (1) ND (3) ND (1) ND 6.2 (1) ND (100)09/14/09 --- 47.01 --- 127.10 No Analytical Results09/23/09 --- 47.07 --- 127.05 1.4 (1) ND (1) ND (3) ND (1) 1.4 14.0 (1) ND (100)

MW-47 Screen: 40.0-60.0 ft bgs TOC: 171.50 ft03/18/09 --- 46.90 --- 124.59 No Analytical Results03/31/09 --- 46.65 --- 124.85 250.0 (2) ND (1) 77.5 (3) 63.0 (1) 390.5 19.0 (1) 1,600.0 (500)09/14/09 --- 45.55 --- 125.94 No Analytical Results09/23/09 --- 45.61 --- 125.89 160.0 (1) ND (1) 46.1 (3) 34.0 (1) 240.1 16.0 (1) 680.0 (100)

MW-48 Screen: 38.0-58.0 ft bgs TOC: 165.96 ft03/18/09 --- 42.91 --- 123.04 No Analytical Results03/31/09 --- 42.52 --- 123.44 ND (1) ND (1) ND (3) ND (1) ND 4.2 (1) ND (100)09/14/09 --- 41.78 --- 124.17 No Analytical Results09/23/09 --- 41.81 --- 124.15 ND (1) ND (1) ND (3) ND (1) ND 1.4 (1) ND (100)

MW-49 Screen: 33.0-53.0 ft bgs TOC: 159.15 ft03/18/09 --- 45.81 --- 113.34 No Analytical Results








PERIOD: 1/1/2009 - 12/31/2009


MW-49 Screen: 33.0-53.0 ft bgs TOC: 159.15 ft03/31/09 --- 45.78 --- 113.37 ND (2) ND (2) ND (6) ND (2) ND 250.0 (2) 210.0 (100)09/14/09 --- 44.78 --- 114.37 No Analytical Results09/23/09 --- 44.82 --- 114.33 ND (1) ND (1) ND (3) ND (1) ND 180.0 (1) 250.0 (100)

MW-50 Screen: 31.0-51.0 ft bgs TOC: 156.12 ft03/18/09 --- 38.45 --- 117.67 No Analytical Results03/31/09 --- 38.44 --- 117.68 4.1 (1) ND (1) ND (3) ND (1) 4.1 110.0 (1) 230.0 (100)09/14/09 --- 37.51 --- 118.61 No Analytical Results09/23/09 --- 37.51 --- 118.61 3.6 (1) ND (1) ND (3) ND (1) 3.6 100.0 (1) 190.0 (100)

MW-51 Screen: 44.0-64.0 ft bgs TOC: 158.12 ft03/18/09 --- 50.35 --- 107.76 No Analytical Results03/31/09 --- 55.30 --- 102.82 21.0 (1) ND (1) ND (3) ND (1) 21.0 76.0 (1) 240.0 (100)09/14/09 --- 49.51 --- 108.60 No Analytical Results09/23/09 --- 49.46 --- 108.66 13.0 (1) ND (1) ND (3) ND (1) 13.0 47.0 (1) 160.0 (100)


MW-53 Screen: 5.5-10.5 ft bgs TOC: 116.18 ft03/18/09 --- 6.56 --- 109.62 No Analytical Results03/23/09 --- 6.54 --- 109.64 7.8 (1) ND (1) 3.9 (3) ND (1) 11.7 150.0 (1) 150.0 (100)09/14/09 Obstructed by Hydrasleeve sampler09/21/09 --- 5.80 --- 110.38 9.2 (1) ND (2) ND (6) ND (2) 9.2 220.0 (2) 290.0 (100)









PERIOD: 1/1/2009 - 12/31/2009



PTW-A Screen: 40.0-65.0 ft bgs TOC: 172.28 ft03/18/09 --- 41.81 --- 130.46 No Analytical Results04/07/09 --- 38.77 --- 133.51 2.7 (1) ND (1) 9.4 (3) ND (1) 12.1 5.2 (1) ND (100)09/14/09 --- 35.98 --- 136.29 No Analytical Results09/29/09 System 4.2 (1) ND (1) 6.3 (3) ND (1) 10.5 ND (1) ND (100)

PTW-B Screen: 34.0-54.0 ft bgs TOC: 171.75 ft03/18/09 --- 41.90 --- 129.85 No Analytical Results04/02/09 --- 37.50 --- 134.25 200.0 (2) 57.0 (2) 600.0 (6) 460.0 (2) 1,317.0 140.0 (2) 2,700.0 (100)09/14/09 --- 34.30 --- 137.45 No Analytical Results09/29/09 System 67.0 (1) 9.7 (1) 73.0 (3) 55.0 (1) 204.7 160.0 (1) 600.0 (100)

RW-1 Screen: 34.0-54.0 ft bgs TOC: 173.36 ft03/18/09 --- 47.86 --- 125.50 No Analytical Results04/01/09 --- 42.78 --- 130.58 890.0 (5) 38.0 (5) 700.0 (15) 640.0 (5) 2,268.0 700.0 (5) 4,100.0 (100)09/14/09 --- 46.01 --- 127.35 No Analytical Results09/29/09 --- 41.30 --- 132.06 1,100.0 (5) 64.0 (5) 860.0 (15) 820.0 (5) 2,844.0 550.0 (5) 4,300.0 (500)

RW-2 Screen: 30.0-55.0 ft bgs TOC: 172.21 ft03/18/09 --- 56.51 --- 115.70 No Analytical Results04/02/09 --- 40.72 --- 131.49 1,500.0 (20) 330.0 (20) 2,800.0 (60) 3,200.0 (20) 7,830.0 850.0 (20) 12,000.0 (500)09/14/09 Top of pump at 43.40 ft09/29/09 System 2,100.0 (20) 280.0 (20) 1,750.0 (60) 2,500.0 (20) 6,630.0 2,700.0 (20) 10,000.0 (1000)








PERIOD: 1/1/2009 - 12/31/2009


RW-3 Screen: 28.0-48.0 ft bgs TOC: 171.62 ft03/18/09 --- 49.95 --- 121.67 No Analytical Results04/01/09 --- 38.71 --- 132.91 580.0 (10) 280.0 (10) 1,820.0 (30) 2,300.0 (10) 4,980.0 200.0 (10) 8,800.0 (1000)09/14/09 Top of pump at 23.99 ft09/29/09 System 480.0 (20) 350.0 (20) 2,360.0 (60) 3,600.0 (20) 6,790.0 38.0 (20) 9,100.0 (500)

VP-4 Screen: UNK TOC: 172.58 ft09/14/09 --- 34.53 --- 138.05 No Analytical Results



APPENDIX D

SOIL VAPOR MONITORING DATA

PERIOD: 7/1/2008 - 12/31/2009

Oxygen Carbon Dioxide MethaneDate Percent Percent Percent

VW-109/18/08 ND (3.9) ND (4.6) ND (5.4) ND (5.4) ND (5.4) ND (4.4) ND (13) 5.7 15.3 0.003/19/09 ND (4) ND (4.8) ND (5.5) ND (5.5) ND (5.5) ND (4.6) 38 (14) 6.6 8.2 0.009/17/09 ND (3.9) ND (4.6) ND (5.4) ND (5.4) ND (5.4) ND (4.4) ND (13) 1.0 13.3 0.0

VW-209/18/08 ND (7.7) ND (9.1) ND (10) ND (10) ND (10) 49 (8.7) ND (26) 12.1 9.5 0.003/19/09 25 (4) ND (4.7) ND (5.4) ND (5.4) ND (5.4) 62.0 (4.5) ND (14) 12.5 5.3 3.609/17/09 14 (8.2) ND (9.7) ND (11) ND (11) ND (11) 31.0 (9.3) ND (28) 11.4 9.7 0.3

VW-0309/18/08 6.6 (3.7) 27 (4.4) 41 (5.0) 69 (5.0) 65 (5.0) 5.2 (4.2) 540 (12) 13.5 6.8 0.003/19/09 ND (3.9) ND (4.6) ND (5.2) ND (5.2) ND (5.2) ND (4.4) 34 (13) 17.0 2.6 0.009/17/09 ND (3.9) ND (4.6) ND (5.4) ND (5.4) ND (5.4) ND (4.4) 16 (13) 17.9 3.4 0.0

Notes:1) Reporting limit shown in parenthesis.2) Analytical results were rounded.3) ND: Not Detected above reporting limit.4) NS: Analyte was not sampled.5) Well VW-03 was reinstalled in February 2008.6) Well VW-04 was not sampled during the reporting period due to the presence of water.

Difluoroethane

TABLE D-1. SOIL VAPOR MONITORING REPORTSEMI-ANNUAL PROGRESS REPORT: JULY THROUGH DECEMBER 2009

FORMER CHEVRON FACILITY 1222085801 RIGGS ROAD CHILLUM, MARYLAND

Tolueneµg/m3

Ethyl-benzene

µg/m3 MTBEµg/m3

o-Xyleneµg/m3

Benzeneµg/m3

m,p-Xylene µg/m3 µg/m3

APP_D Soil Vapor.xls Table D1: Page 1 of 1 Printed On: 1/14/2010

APPENDIX E

VAPOR MITIGATION SYSTEM DATA

Address DateAverage Flow Velocity

(ft/min)Air Flow Rate

(standard ft3/min)

Cross-Slab Differential Pressure

(in. H2O)03/26/09 144 13 -0.00704/27/09 182 16 0.00005/07/09 228 20 -0.00606/29/09 150 3 -0.01107/27/09 217 4 -0.00408/24/09 1804 34 -0.00601/06/09 97 8 -0.01502/09/09 530 1 46 1 -0.03003/26/09 195 17 -0.04504/24/09 551 48 -0.03008/24/09 2434 64 -0.00303/31/09 99 9 -0.039

10/19/2009 176.5 15 NM5

11/16/2009 243 4 -0.004-0.016-0.025

Notes:

2. Initial readings collected immediately following vapor mitigation system start-up. 3. The resident at 746 Oglethorpe Street turned the system off shortly after start up. 4. Weekend preceeding 8/24/09 readings (8/22, 23) was a large rainstorm producing 1.4 inches of precipitation.

5. NM: Not measured due to equipment malfunction.

5824 Eastern Avenue

5818 Eastern Avenue2

discharge pipe, creating turbulence and a falsely high reading.1. The average flow velocity appears erroneous. The instrument reading was taken too close to the wall of the

EPA Sub-Slab Depressurization GoalASTM Sub-Slab Depressurization Goal

746 Oglethorpe Street3

Table E-1. Vapor Mitigation System MeasurementsSemi-Annual Progress Report: January through June 2009


Table E1_VMS Measurements.xls Page 1 of 1 Printed on: 1/14/2010

APPENDIX F

MANN KENDALL STATISTICAL ANALYSIS

1

Mann-Kendall Statistical Analysis Former Chevron Facility 122208

5801 Riggs Road, Chillum, Maryland December 2009

The Mann-Kendall statistical analysis was used to determine trends in dissolved-phase hydrocarbon concentrations at the Chillum site. These data will be used to support the site-wide groundwater remedial strategy of monitored natural attenuation (MNA). SITE-WIDE GROUNDWATER REMEDIAL OBJECTIVE The approved Corrective Measures Study (CMS) (Gannett Fleming, 2007) presents a site-wide groundwater remediation strategy that includes MNA. One method to demonstrate that MNA is effective at decreasing hydrocarbon concentrations is the statistical evaluation of sampling results. The Mann-Kendall statistical analysis was selected as an industry-accepted method to provide evidence that dissolved-phase hydrocarbon concentrations are stable and/or decreasing over time. MANN-KENDALL BACKGROUND The Mann-Kendall statistical analysis is used to determine if dissolved-phase hydrocarbon concentrations in groundwater are increasing, decreasing, or stable over time. The technique requires that individual wells with the highest concentrations along the centerline of mapped dissolved-phase hydrocarbons in the groundwater be used to identify trends in dissolved-phase hydrocarbon concentrations over time. The Mann-Kendall statistical analysis compares every data point (e.g., semi-annual sampling event results) in a data set to every other data point (sampling result) for a particular well along the centerline of mapped dissolved-phase hydrocarbons. A value of 1 or -1 is assigned as each data point is compared based on whether it is higher or lower than the previous. As few as 5 and as many as 10 data points may be used in the analysis; however, the greater the number of data points used, the more reliable the trend analysis becomes. The output of the analysis is a Mann-Kendall S statistic for the data set for each well. The S statistic shows: 1) the confidence level in the data; 2) the strength of the data trend; and 3) the variability in the data (Wiedemeier, 1999). The absolute value of S is then compared to the 95 percent confidence level in the trend. A positive S suggests an increasing trend and a negative S suggests a decreasing tend. An S outside of the 95 percent confidence level is considered to have no trend (e.g., a stable trend). The 95 percent confidence interval is used as a conservative guide to establishing trends. The analysis is robust because missing values are allowed and the data set need not conform to any particular distribution. Also, laboratory data reported as below the laboratory detection limit can be used and are reported as half the laboratory detection limit (US EPA, 1998). This approach can be used because the Mann-Kendall methodology uses only the relative magnitudes of the laboratory data rather than actual measured values (Gilbert, 1987).

2

METHODS A Geoprobe® was used to obtain an exhaustive profile of groundwater at the site during 2001 and 2002. The Geoprobe groundwater data were used to map the centerline of dissolved-phase hydrocarbon concentrations in groundwater and subsequently install monitoring wells along the centerline of dissolved-phase hydrocarbons (Gannett Fleming, 2006). The presence of a mappable clay body in the subsurface (as evidenced from the Geoprobe soil investigation) splits the dissolved-phase hydrocarbons in groundwater into two separate centerlines. As a result, these two centerlines are identified as the west centerline and the east centerline (Figure 1). Wells used to define the centerlines are as follows:

West Centerline East Centerline MW-22 MW-22

MW-24B GP-39A MW-26B MW-47 MW-33B GP-2E(45-50)

MW-25B MW-27B MW-53

The Mann-Kendall statistical analysis was performed using benzene and methyl tert butyl ether (MTBE) for each well within the centerlines. Mann-Kendall trend analysis tables for each well along the west and east centerlines are presented in Attachment A and B, respectively. The 10 most recent groundwater sampling results were used in the analysis. Values that were reported as below the laboratory detection limit were assigned a value of half of the detection limit. RESULTS OF MANN-KENDALL ANALYSES Tables 1 and 2 provide groundwater sampling results for individual wells along the west and east centerlines. Table 3 provides a general summary of the Mann-Kendall statistical analyses performed for both benzene and MTBE. Several trends were noted that are provided below. Results of the analysis for the west centerline are as follows:

• Benzene and MTBE concentrations in MW-22 were decreasing; • Benzene concentrations in MW-24B were decreasing and MTBE concentrations

were stable;

• Benzene and MTBE concentrations in MW-26B were stable; and

• Benzene and MTBE concentrations in MW-33B were decreasing. Results of the analysis for the east centerline are as follows:

3

• Benzene and MTBE concentrations in MW-22 were decreasing; • Benzene concentrations in GP-39A were increasing, which may be a result of an

extended period in 2004 and 2005 when the remediation system was turned off for construction. The range of benzene concentrations since March 2007 has only varied from 2,100 to 3,100μg/L, therefore the recent data trend over the last 2.5 years is stable. This well will be over drilled and added to the expanded Dual Phase Extraction (DPE) system. MTBE concentrations were stable;

• Benzene and MTBE concentrations in MW-47 were stable;

• Benzene concentrations in GP-2E(45-50) were decreasing and MTBE concentrations were stable;

• Benzene concentrations in MW-25B were stable and MTBE concentrations were

decreasing;

• Benzene and MTBE concentrations in MW-27B were decreasing; and

• Benzene concentrations in MW-53 were stable and MTBE concentrations were increasing. However, the range of MTBE concentrations since October 2006 has only varied from 110 to 270μg/L, therefore the recent data trend over the last 3 years is stable. This well is also the farthest from the service station. It will take a long time for remediation efforts at the service station to affect this area.

SUMMARY AND CONCLUSIONS Dissolved-phase hydrocarbon concentrations for centerline wells were either stable or decreasing based on long and short-term sampling data. Therefore, the overall trend for each centerline was stable. This is to be expected because active remediation is not complete near the service station. Based on this line of evidence, MNA was working to decrease dissolved-phase hydrocarbon concentrations at the site. Based on ten sampling events conducted since 2004, benzene and MTBE concentrations along the west centerline were stable or decreasing for all wells. The east centerline wells show a similar tendency. All wells were either stable or decreasing except benzene in GP-39A and MTBE in MW-53. However, based on short term sampling data from the last 3 years, the trend in these wells is stable. RECOMMENDATION The following corrective measures will be implemented at the site:

• Area A - an expanded DPE system, to include the addition of four vertical recovery wells and one angle recovery well;

• Area B - Two In-Situ Groundwater Remediation (ISGR) Wells to be installed in the residential neighborhood (Oglethorpe Alley); and

• Area C - an Oxygen Reactive Zone in the residential neighborhood (Nicholson Alley), to include a series of in-situ oxygen emitting probes.

4

As part of the corrective measures, wells MW-22 and GP-39A will be over drilled and added to the expanded DPE system in Area A. MW-24B will be near or within the radius of influence of the ISGR Well system in Area B. MW-26B will be adjacent to and down gradient of the Oxygen Reactive Zone in Area C. The Mann Kendall statistical analysis will continue to be performed on an annual basis using the semi-annual groundwater monitoring data for wells along the west and east centerlines to confirm that hydrocarbon concentrations are continuing to decrease or remain stable. The next Mann Kendall update will be submitted in January 2011.

5

REFERENCES Gannett Fleming, 2006, Site Investigation Report, Former Chevron Facility 122208, 5801 Riggs Road, Chillum Maryland, dated January 2006. Gannett Fleming, 2007, Corrective Measures Study (CMS), Former Chevron Facility 122208, 5801 Riggs Road, Chillum Maryland, dated July 2007. Gilbert, Richard O., 1987, Statistical Methods for Environmental Pollution Monitoring, Van Nostrand Reinhold, NY, NY, 319 pages. U.S. Environmental Protection Agency (EPA), 1998, Guidance for Data Quality Assessment, EPA/600/R-96/084. Wiedemeier Todd H., et. al., 1999, Natural Attenuation of Fuels and Chlorinated Solvents in the Subsurface, John Wiley and Sons, Inc. NY, NY, 617 pages.

TABLES

Date

MW-2206/08/04 5,620.0 (100) 866.0 (20)08/03/04 7,960.0 (200) 1,620.0 (10)09/07/05 8,790.0 (50) 1,780.0 (50)03/23/06 6,860.0 (100) 2,020.0 (100)10/02/06 7,900.0 (100) 1,100.0 (100)03/26/07 2,400.0 (100) 570.0 (100)10/01/07 7,000.0 (100) 1,000.0 (100)03/31/08 4,900.0 (100) 710.0 (100)09/25/08 1,100.0 (5) 1,100.0 (5)03/30/09 5,900.0 (100) 680.0 (100)09/28/09 4,200.0 (100) 420.0 (100)

MW-24B06/08/04 431.0 (10) 9.3 (1)08/02/04 474.0 (10) 9.6 (1)09/15/05 497.0 (10) 3.6 (1)03/27/06 864.0 (20) 4.0 (1)10/04/06 540.0 (50) ND (50)03/27/07 5.6 (1) ND (1)10/02/07 310.0 (20) ND (20)04/01/08 110.0 (20) ND (20)09/24/08 ND (20) ND (20)03/27/09 17.0 (20) ND (20)09/29/09 ND (5) ND (5)

MW-26B06/07/04 30.5 (1) 112.0 (1)07/30/04 34.4 (1) 114.0 (1)09/16/05 24.9 (1) 168.0 (1)03/28/06 144.0 (1) 221.0 (10)10/05/06 100.0 (1) 210.0 (1)03/28/07 140.0 (1) 270.0 (1)10/04/07 110.0 (1) 230.0 (1)04/02/08 94.0 (1) 170.0 (1)09/23/08 110.0 (1) 200.0 (1)03/25/09 130.0 (1) 230.0 (1)09/22/09 150.0 (1) 200.0 (1)

MW-33B06/02/04 1,040.0 (20) 770.0 (20)07/27/04 1,000.0 (20) 744.0 (20)09/13/05 ND (1) 698.0 (10)03/28/06 974.0 (10) 653.0 (10)10/05/06 760.0 (5) 520.0 (5)03/29/07 670.0 (5) 400.0 (5)10/05/07 540.0 (2) 410.0 (2)04/02/08 520.0 (5) 400.0 (2)09/23/08 340.0 (2) 230.0 (2)03/24/09 380.0 (2) 220.0 (2)09/21/09 380.0 (2) 240.0 (2)

Notes:1) Reporting limit shown in parenthesis.2) Analytical results were rounded.3) ND: Not Detected above reporting limit.4) BTEX summed before rounding.

PERIOD: June 2004 - September 2009

Benzeneµg/l

Methyl-t-butyl etherµg/l

Table 1. Groundwater Monitoring Results - West CenterlineMann-Kendall Statistical AnalysisFormer Chevron Facility 122208

5801 Riggs Road, Chillum, Maryland

Table 1_West_Centerline.xls Table 1: Page 1 of 1 Printed On: 1/14/2010

Date

GP-2E(45-50)04/18/02 170.0 (2) 795.0 (20)12/19/02 46.3 (1) 600.0 (10)05/19/04 28.7 (1) 756.0 (10)08/16/04 60.2 (1) 656.0 (5)12/15/04 117.0 (1) 522.0 (10)03/21/05 189.0 (1) 610.0 (10)05/26/05 172.0 (1) 803.0 (10)09/14/05 134.0 (1) 501.0 (5)12/20/05 71.4 (1) 394.0 (10)10/02/06 78.0 (5) 420.0 (5)03/26/07 50.0 (5) 400.0 (5)10/01/07 34.0 (2) 470.0 (2)03/31/08 8.0 (2) 330.0 (2)09/25/08 ND (2) 370.0 (2)03/30/09 ND (2) 350.0 (2)09/28/09 ND (2) 450.0 (2)

GP-39A10/02/02 ND (1) ND (1)03/26/03 ND (1) 1.1 (1)06/17/03 ND (1) 1.1 (1)09/23/03 ND (1) 2.1 (1)12/10/03 535.0 (10) 1,770.0 (10)03/24/04 570.0 (20) 1,940.0 (20)05/18/04 473.0 (10) 1,680.0 (10)08/16/04 476.0 (20) 2,060.0 (20)12/16/04 725.0 (50) 2,520.0 (50)03/21/05 7.1 (1) 3,200.0 (20)05/26/05 905.0 (50) 3,550.0 (50)09/08/05 721.0 (10) 2,490.0 (100)12/19/05 995.0 (25) 3,360.0 (25)03/22/06 1,570.0 (50) 5,960.0 (50)09/28/06 2,500.0 (25) 6,500.0 (25)03/22/07 2,600.0 (20) 5,800.0 (20)09/24/07 2,300.0 (25) 5,200.0 (25)03/27/08 2,100.0 (20) 5,400.0 (20)09/30/08 2,100.0 (25) 4,800.0 (25)03/31/09 2,200.0 (25) 4,900.0 (25)09/23/09 3,100.0 (25) 4,700.0 (25)

MW-2206/08/04 5,620.0 (100) 866.0 (20)08/03/04 7,960.0 (200) 1,620.0 (10)09/07/05 8,790.0 (50) 1,780.0 (50)03/23/06 6,860.0 (100) 2,020.0 (100)10/02/06 7,900.0 (100) 1,100.0 (100)03/26/07 2,400.0 (100) 570.0 (100)10/01/07 7,000.0 (100) 1,000.0 (100)03/31/08 4,900.0 (100) 710.0 (100)09/25/08 1,100.0 (5) 1,100.0 (5)03/30/09 5,900.0 (100) 680.0 (100)09/28/09 4,200.0 (100) 420.0 (100)

MW-25B11/22/04 456.0 (10) 502.0 (10)


PERIOD: April 2002 - September 2009

Benzeneµg/l


Table 2. Groundwater Monitoring Results - East CenterlineMann-Kendall Statistical AnalysisFormer Chevron Facility 122208


Table 2_East Centerline.xls Table 1: Page 1 of 2 Printed On: 1/14/2010

Date

PERIOD: April 2002 - September 2009

Benzeneµg/l


Table 2. Groundwater Monitoring Results - East CenterlineMann-Kendall Statistical AnalysisFormer Chevron Facility 122208


MW-25B09/15/05 ND (1) 386.0 (10)03/24/06 403.0 (10) 461.0 (10)10/04/06 470.0 (5) 550.0 (5)03/27/07 320.0 (2) 370.0 (2)10/03/07 340.0 (2) 490.0 (2)04/01/08 180.0 (2) 310.0 (2)09/24/08 240.0 (2) 350.0 (2)03/27/09 450.0 (2) 410.0 (2)09/22/09 170.0 (2) 260.0 (2)

MW-27B06/02/04 193.0 (1) 534.0 (10)07/28/04 142.0 (1) 507.0 (10)09/16/05 146.0 (1) 417.0 (20)03/28/06 168.0 (1) 451.0 (10)10/05/06 150.0 (5) 370.0 (5)03/28/07 200.0 (2) 530.0 (2)10/04/07 82.0 (2) 310.0 (2)04/02/08 34.0 (1) 240.0 (2)09/23/08 37.0 (1) 240.0 (1)03/25/09 19.0 (1) 240.0 (1)09/22/09 6.5 (1) 160.0 (1)

MW-4711/19/04 116.0 (1) 27.2 (1)09/06/05 315.0 (5) 17.6 (1)03/22/06 459.0 (10) 13.3 (1)09/28/06 380.0 (2) 22.0 (2)03/22/07 240.0 (2) 58.0 (2)09/24/07 260.0 (1) ND (1)03/27/08 360.0 (2) ND (2)09/29/08 230.0 (2) 15.0 (2)03/31/09 250.0 (2) 19.0 (1)09/23/09 160.0 (1) 16.0 (1)

MW-5305/03/05 ND (1) 66.4 (1)06/08/05 ND (1) 97.0 (1)09/14/05 ND (1) 88.1 (1)03/28/06 4.0 (1) 103.0 (1)10/06/06 54.0 (1) 240.0 (1)03/29/07 15.0 (1) 110.0 (1)10/05/07 61.0 (2) 270.0 (2)04/03/08 17.0 (1) 160.0 (1)09/22/08 23.0 (1) 160.0 (1)03/23/09 7.8 (1) 150.0 (1)09/21/09 9.2 (1) 220.0 (2)


Table 2_East Centerline.xls Table 1: Page 2 of 2 Printed On: 1/14/2010

West Centerline - Benzene

Well IDDistance from

MW-22 (ft) Trend Date RangeNumber of Data Points

MW-22 0 Decreasing 8/3/2004 - 9/28/2009 10MW-24B 232 Decreasing 8/2/2004 - 9/29/2009 10MW-26B 666 Stable 7/30/2004 - 9/22/2009 10MW-33B 944 Decreasing 7/27/2004 - 9/21/2009 10

West Centerline - MTBE



MW-22 0 Decreasing 8/3/2004 - 9/28/2009 10MW-24B1 232 Stable 6/8/2004 - 9/29/2009 10MW-26B 666 Stable 7/30/2004 - 9/22/2009 10MW-33B 944 Decreasing 7/27/2004 - 9/21/2009 10

East Centerline - Benzene



MW-22 0 Decreasing 8/3/2004 - 9/28/2009 10GP-39A 109 Increasing 9/8/2005 - 9/23/2009 10MW-47 292 Stable 11/19/2004 - 9/23/2009 10GP-2E (45-50) 445 Decreasing 5/26/2005 - 9/28/2009 10MW-25B 618 Stable 11/22/2004 - 9/22/2009 10MW-27B 991 Decreasing 7/28/2004 - 9/22/2009 10MW-53 1163 Stable 6/8/2005 - 9/21/2009 10

East Centerline - MTBE



MW-22 0 Decreasing 8/3/2004 - 9/28/2009 10GP-39A 109 Stable 9/8/2005 - 9/23/2009 10MW-47 292 Stable 11/19/2004 - 9/23/2009 10GP-2E (45-50) 445 Stable 5/26/2005 - 9/28/2009 10MW-25B 618 Decreasing 11/22/2004 - 9/22/2009 10MW-27B 991 Decreasing 7/28/2004 - 9/22/2009 10MW-53 1163 Increasing 6/8/2005 - 9/21/2009 10

Note:1. MTBE data collected from MW-24B on 10/04/06 were excluded from the data setbecause the value was reported below a laboratory detection limit of 50 µg/L.

Former Chevron Facility 122208Mann-Kendall Statistical Analysis

Table 3. Mann-Kendall Results Summary


Table 3_MK Summary Table.xls Page 1 of 1 Printed on: 1/14/2010

FIGURES

Eastern Avenue

Riggs

Roa

d

Kennedy Street

Madison Street

Nicholson Street

Oglethorpe Street

8th Street

MW-13 GP-41AMP-40

GP-39A

MW-23

PTW-A MP-7

GP-27AMP-20MP-30

GP-38AGP-30A

MW-22

MW-17

MW-4

MW-15GP-35A

MW-7

MW-5VP-4

MW-3

MW-6MW-2

GP-24AMW-1

MW-12

MW-21

PTW-B

MW-18

MW-41A

MW-32

MW-44B

MW-29B

MW-33AMW-28B

MW-42MW-26B

MW-31B

MW-43A

MW-30

MW-24B GP-7A(40-45)GP-9A(30-35) GP-11A(35-40)

GP-2E(55-60)

MW-39MW-38

MW-20

MW-16

GP-7A(30-35)GP-7A(25-30)

GP-7A(20-25)GP-9A(25-30)

GP-9A(20-25)GP-11A(30-35)

GP-11A(25-30)GP-11A(20-25)

MW-25A

GP-2E(50-55) GP-2E(45-50)

MW-40

MW-26AMW-43B

GP-2F(50-55)

MW-41B

MW-37

MW-31A MW-28A

MW-33BMW-33C

MW-44A

MW-27AMW-27B

MW-29A

GP-2F(45-50)

(2.41)

RW-3 RW-2

RW-1

MW-45

MW-46

MW-19

MW-47

MW-48MW-49

MW-50

MW-25B

MW-51

MW-39R

MW-53

MW-54

MW-33SMW-52

MW-55

GP-44A

West Centerline

East Centerline

J:\44

738_

Chillu

m\SI

_Rep

ort\La

youts

\Man

n_Ke

ndall

_Ana

lysis_

11x1

7.mxd

Centerlines for Mann-Kendall Analysis

REVISIONSDESCRIPTION

DATE BYNO. DESIGNED GIS SCALE

APPROVEDCHECKED

RWS CERAS NOTED

BALTIMORE, MARYLAND

SHEET NO.

1GF PROJECT NO.

DATE

GIS FILE07-17-08

44738

Mann_Kendall_Analysis_11x17.mxd

FORMER CHEVRON FACILITY NO. 122208CHILLUM, MARYLAND

RWS

Scale: 1 Inch = 100 Feet

LegendFormer Chevron FacilityNo. 122208 Property LineProperty LinesStructures/Sidewalks

Monitoring Well

Dual-Phase ExtractionRecovery Well Soil Vapor ExtractionRecovery Well

Clay Body

0 50 100 150 20025Feet

Mann-Kendall Analysis Centerline

ATTACHMENT A

Mann-Kendall Analysis Tables – West Centerline

Mann-Kendall Statistical Method Worksheet

Site-- ChillumCompound-- BenzeneWell-- MW-22

Event 1 Event 2 Event 3 Event 4 Event 5 Event 6 Event 7 Event 8 Event 9 Event 10 EventsConcentration 7,960 8,790 6,860 7,900 2,400 7,000 4,900 1,100 5,900 4,200 10

-- -- -- -- -- -- -- -- -- -- SumCompared to Event 1 ***** 1 -1 -1 -1 -1 -1 -1 -1 -1 -7Compared to Event 2 ***** ***** -1 -1 -1 -1 -1 -1 -1 -1 -8Compared to Event 3 ***** ***** ***** 1 -1 1 -1 -1 -1 -1 -3Compared to Event 4 ***** ***** ***** ***** -1 -1 -1 -1 -1 -1 -6Compared to Event 5 ***** ***** ***** ***** ***** 1 1 -1 1 1 3Compared to Event 6 ***** ***** ***** ***** ***** ***** -1 -1 -1 -1 -4Compared to Event 7 ***** ***** ***** ***** ***** ***** ***** -1 1 -1 -1Compared to Event 8 ***** ***** ***** ***** ***** ***** ***** ***** 1 1 2Compared to Event 9 ***** ***** ***** ***** ***** ***** ***** ***** ***** -1 -1

Mann-Kendall Statistic 'S' = -25

Statistical Confidence Level

I S I ≥ 15 I S I ≥ 20

Result Decreasing Trend Result Decreasing Trend

WEST CENTERLINE - MW-22 - BENZENE

>90% Confidence >95% Confidence


Site-- ChillumCompound-- MTBEWell-- MW-22

Event 1 Event 2 Event 3 Event 4 Event 5 Event 6 Event 7 Event 8 Event 9 Event 10 EventsConcentration 1,620 1,780 2,020 1,100 570 1,000 710 1,100 680 420 10

-- -- -- -- -- -- -- -- -- -- SumCompared to Event 1 ***** 1 1 -1 -1 -1 -1 -1 -1 -1 -5Compared to Event 2 ***** ***** 1 -1 -1 -1 -1 -1 -1 -1 -6Compared to Event 3 ***** ***** ***** -1 -1 -1 -1 -1 -1 -1 -7Compared to Event 4 ***** ***** ***** ***** -1 -1 -1 0 -1 -1 -5Compared to Event 5 ***** ***** ***** ***** ***** 1 1 1 1 -1 3Compared to Event 6 ***** ***** ***** ***** ***** ***** -1 1 -1 -1 -2Compared to Event 7 ***** ***** ***** ***** ***** ***** ***** 1 -1 -1 -1Compared to Event 8 ***** ***** ***** ***** ***** ***** ***** ***** -1 -1 -2Compared to Event 9 ***** ***** ***** ***** ***** ***** ***** ***** ***** -1 -1



I S I ≥ 15 I S I ≥ 20


WEST CENTERLINE - MW-22 - MTBE



Site-- ChillumCompound-- BenzeneWell-- MW-24B

Event 1 Event 2 Event 3 Event 4 Event 5 Event 6 Event 7 Event 8 Event 9 Event 10 EventsConcentration 474 497 864 540 6 310 110 10 17 3 10

-- -- -- -- -- -- -- -- -- -- SumCompared to Event 1 ***** 1 1 1 -1 -1 -1 -1 -1 -1 -3Compared to Event 2 ***** ***** 1 1 -1 -1 -1 -1 -1 -1 -4Compared to Event 3 ***** ***** ***** -1 -1 -1 -1 -1 -1 -1 -7Compared to Event 4 ***** ***** ***** ***** -1 -1 -1 -1 -1 -1 -6Compared to Event 5 ***** ***** ***** ***** ***** 1 1 1 1 -1 3Compared to Event 6 ***** ***** ***** ***** ***** ***** -1 -1 -1 -1 -4Compared to Event 7 ***** ***** ***** ***** ***** ***** ***** -1 -1 -1 -3Compared to Event 8 ***** ***** ***** ***** ***** ***** ***** ***** 1 -1Compared to Event 9 ***** ***** ***** ***** ***** ***** ***** ***** ***** -1 -1



I S I ≥ 15 I S I ≥ 20


WEST CENTERLINE - MW-24B - BENZENE



Site-- ChillumCompound-- MTBEWell-- MW-24B


-- -- -- -- -- -- -- -- -- -- SumCompared to Event 1 ***** 1 -1 -1 -1 1 1 1 1 -1 1Compared to Event 2 ***** ***** -1 -1 -1 1 1 1 1 -1 0Compared to Event 3 ***** ***** ***** 1 -1 1 1 1 1 -1 3Compared to Event 4 ***** ***** ***** ***** -1 1 1 1 1 -1 2Compared to Event 5 ***** ***** ***** ***** ***** 1 1 1 1 1 5Compared to Event 6 ***** ***** ***** ***** ***** ***** 0 0 0 -1 -1Compared to Event 7 ***** ***** ***** ***** ***** ***** ***** 0 0 -1 -1Compared to Event 8 ***** ***** ***** ***** ***** ***** ***** ***** 0 -1 -1Compared to Event 9 ***** ***** ***** ***** ***** ***** ***** ***** ***** -1 -1

Mann-Kendall Statistic 'S' = 7


I S I ≥ 15 I S I ≥ 20

Result No Trend Result No Trend

WEST CENTERLINE - MW-24B - MTBE





-- -- -- -- -- -- -- -- -- -- SumCompared to Event 1 ***** -1 1 1 1 1 1 1 1 1 7Compared to Event 2 ***** ***** 1 1 1 1 1 1 1 1 8Compared to Event 3 ***** ***** ***** -1 -1 -1 -1 -1 -1 1 -5Compared to Event 4 ***** ***** ***** ***** 1 1 -1 1 1 1 4Compared to Event 5 ***** ***** ***** ***** ***** -1 -1 -1 -1 1 -3Compared to Event 6 ***** ***** ***** ***** ***** ***** -1 0 1 1 1Compared to Event 7 ***** ***** ***** ***** ***** ***** ***** 1 1 1 3Compared to Event 8 ***** ***** ***** ***** ***** ***** ***** ***** 1 1 2Compared to Event 9 ***** ***** ***** ***** ***** ***** ***** ***** ***** 1 1



I S I ≥ 15 I S I ≥ 20

Result Increasing Trend Result No Trend






-- -- -- -- -- -- -- -- -- -- SumCompared to Event 1 ***** 1 1 1 1 1 1 1 1 1 9Compared to Event 2 ***** ***** 1 1 1 1 1 1 1 1 8Compared to Event 3 ***** ***** ***** -1 1 1 -1 -1 1 -1 -1Compared to Event 4 ***** ***** ***** ***** 1 1 -1 -1 1 -1Compared to Event 5 ***** ***** ***** ***** ***** -1 -1 -1 -1 -1 -5Compared to Event 6 ***** ***** ***** ***** ***** ***** -1 -1 0 -1 -3Compared to Event 7 ***** ***** ***** ***** ***** ***** ***** 1 1 1 3Compared to Event 8 ***** ***** ***** ***** ***** ***** ***** ***** 1 0 1Compared to Event 9 ***** ***** ***** ***** ***** ***** ***** ***** ***** -1 -1



I S I ≥ 15 I S I ≥ 20






Event 1 Event 2 Event 3 Event 4 Event 5 Event 6 Event 7 Event 8 Event 9 Event 10 EventsConcentration 1,000 1 974 760 670 540 520 340 380 380 10

-- -- -- -- -- -- -- -- -- -- SumCompared to Event 1 ***** -1 -1 -1 -1 -1 -1 -1 -1 -1 -9Compared to Event 2 ***** ***** 1 1 1 1 1 1 1 1 8Compared to Event 3 ***** ***** ***** -1 -1 -1 -1 -1 -1 -1 -7Compared to Event 4 ***** ***** ***** ***** -1 -1 -1 -1 -1 -1 -6Compared to Event 5 ***** ***** ***** ***** ***** -1 -1 -1 -1 -1 -5Compared to Event 6 ***** ***** ***** ***** ***** ***** -1 -1 -1 -1 -4Compared to Event 7 ***** ***** ***** ***** ***** ***** ***** -1 -1 -1 -3Compared to Event 8 ***** ***** ***** ***** ***** ***** ***** ***** 1 1 2Compared to Event 9 ***** ***** ***** ***** ***** ***** ***** ***** ***** 0



I S I ≥ 15 I S I ≥ 20





Site-- ChillumCompound-- MTBE

Well-- MW-33B


-- -- -- -- -- -- -- -- -- -- SumCompared to Event 1 ***** -1 -1 -1 -1 -1 -1 -1 -1 -1 -9Compared to Event 2 ***** ***** -1 -1 -1 -1 -1 -1 -1 -1 -8Compared to Event 3 ***** ***** ***** -1 -1 -1 -1 -1 -1 -1 -7Compared to Event 4 ***** ***** ***** ***** -1 -1 -1 -1 -1 -1 -6Compared to Event 5 ***** ***** ***** ***** ***** 1 0 -1 -1 -1 -2Compared to Event 6 ***** ***** ***** ***** ***** ***** -1 -1 -1 -1 -4Compared to Event 7 ***** ***** ***** ***** ***** ***** ***** -1 -1 -1 -3Compared to Event 8 ***** ***** ***** ***** ***** ***** ***** ***** -1 1Compared to Event 9 ***** ***** ***** ***** ***** ***** ***** ***** ***** 1 1



I S I ≥ 15 I S I ≥ 20





Site-- SmallvilleCompound-- Benzene

Well-- MW-12

Input data from four to ten sampling events in Row 10.

Event 1 Event 2 Event 3 Event 4 Event 5 Event 6 Event 7 Event 8 Event 9 Event 10 EventsConcentration 3,780 1,810 2,630 2,800 2,600 2,000 1,800 130 1,500 140 10

-- -- -- -- -- -- -- -- -- -- SumCompared to Event 1 ***** -1 -1 -1 -1 -1 -1 -1 -1 -1 -9Compared to Event 2 ***** ***** 1 1 1 1 -1 -1 -1 -1Compared to Event 3 ***** ***** ***** 1 -1 -1 -1 -1 -1 -1 -5Compared to Event 4 ***** ***** ***** ***** -1 -1 -1 -1 -1 -1 -6Compared to Event 5 ***** ***** ***** ***** ***** -1 -1 -1 -1 -1 -5Compared to Event 6 ***** ***** ***** ***** ***** ***** -1 -1 -1 -1 -4Compared to Event 7 ***** ***** ***** ***** ***** ***** ***** -1 -1 -1 -3Compared to Event 8 ***** ***** ***** ***** ***** ***** ***** ***** 1 1 2Compared to Event 9 ***** ***** ***** ***** ***** ***** ***** ***** ***** -1 -1




I S I ≥ 15 I S I ≥ 20


ATTACHMENT B

Mann-Kendall Analysis Tables – East Centerline


Site-- ChillumCompound-- Benzene

Well-- MW-22


-- -- -- -- -- -- -- -- -- -- SumCompared to Event 1 ***** 1 -1 -1 -1 -1 -1 -1 -1 -1 -7Compared to Event 2 ***** ***** -1 -1 -1 -1 -1 -1 -1 -1 -8Compared to Event 3 ***** ***** ***** 1 -1 1 -1 -1 -1 -1 -3Compared to Event 4 ***** ***** ***** ***** -1 -1 -1 -1 -1 -1 -6Compared to Event 5 ***** ***** ***** ***** ***** 1 1 -1 1 1 3Compared to Event 6 ***** ***** ***** ***** ***** ***** -1 -1 -1 -1 -4Compared to Event 7 ***** ***** ***** ***** ***** ***** ***** -1 1 -1 -1Compared to Event 8 ***** ***** ***** ***** ***** ***** ***** ***** 1 1 2Compared to Event 9 ***** ***** ***** ***** ***** ***** ***** ***** ***** -1 -1



I S I ≥ 15 I S I ≥ 20


EAST CENTERLINE - MW-22 - BENZENE




Event 1 Event 2 Event 3 Event 4 Event 5 Event 6 Event 7 Event 8 Event 9 Event 10 EventsConcentration 1,620 1,780 2,020 1,100 570 1,000 710 1,100 680 420 10

-- -- -- -- -- -- -- -- -- -- SumCompared to Event 1 ***** 1 1 -1 -1 -1 -1 -1 -1 -1 -5Compared to Event 2 ***** ***** 1 -1 -1 -1 -1 -1 -1 -1 -6Compared to Event 3 ***** ***** ***** -1 -1 -1 -1 -1 -1 -1 -7Compared to Event 4 ***** ***** ***** ***** -1 -1 -1 0 -1 -1 -5Compared to Event 5 ***** ***** ***** ***** ***** 1 1 1 1 -1 3Compared to Event 6 ***** ***** ***** ***** ***** ***** -1 1 -1 -1 -2Compared to Event 7 ***** ***** ***** ***** ***** ***** ***** 1 -1 -1 -1Compared to Event 8 ***** ***** ***** ***** ***** ***** ***** ***** -1 -1 -2Compared to Event 9 ***** ***** ***** ***** ***** ***** ***** ***** ***** -1 -1



I S I ≥ 15 I S I ≥ 20


EAST CENTERLINE - MW-22 - MTBE



Site-- ChillumCompound-- BenzeneWell-- GP-39A

Event 1 Event 2 Event 3 Event 4 Event 5 Event 6 Event 7 Event 8 Event 9 Event 10 EventsConcentration 721 995 1,570 2,500 2,600 2,300 2,100 2,100 2,200 3,100 10

-- -- -- -- -- -- -- -- -- SumCompared to Event 1 ***** 1 1 1 1 1 1 1 1 1 9Compared to Event 2 ***** ***** 1 1 1 1 1 1 1 1 8Compared to Event 3 ***** ***** ***** 1 1 1 1 1 1 1 7Compared to Event 4 ***** ***** ***** ***** 1 -1 -1 -1 -1 1 -2Compared to Event 5 ***** ***** ***** ***** ***** -1 -1 -1 -1 1 -3Compared to Event 6 ***** ***** ***** ***** ***** ***** -1 -1 -1 1 -2Compared to Event 7 ***** ***** ***** ***** ***** ***** ***** 0 1 1 2Compared to Event 8 ***** ***** ***** ***** ***** ***** ***** ***** 1 1 2Compared to Event 9 ***** ***** ***** ***** ***** ***** ***** ***** ***** 1 1



I S I ≥ 15 I S I ≥ 20

Result Increasing Trend Result Increasing Trend

EAST CENTERLINE - GP-39A - BENZENE



Site-- ChillumCompound-- MTBEWell-- GP-39A


-- -- -- -- -- -- -- -- -- -- SumCompared to Event 1 ***** 1 1 1 1 1 1 1 1 1 9Compared to Event 2 ***** ***** 1 1 1 1 1 1 1 1 8Compared to Event 3 ***** ***** ***** 1 -1 -1 -1 -1 -1 -1 -5Compared to Event 4 ***** ***** ***** ***** -1 -1 -1 -1 -1 -1 -6Compared to Event 5 ***** ***** ***** ***** ***** -1 -1 -1 -1 -1 -5Compared to Event 6 ***** ***** ***** ***** ***** ***** 1 -1 -1 -1 -2Compared to Event 7 ***** ***** ***** ***** ***** ***** ***** -1 -1 -1 -3Compared to Event 8 ***** ***** ***** ***** ***** ***** ***** ***** 1 -1 0Compared to Event 9 ***** ***** ***** ***** ***** ***** ***** ***** ***** -1 -1



I S I ≥ 15 I S I ≥ 20


EAST CENTERLINE - GP-39A - MTBE





-- -- -- -- -- -- -- -- -- -- SumCompared to Event 1 ***** 1 1 1 1 1 1 1 1 1 9Compared to Event 2 ***** ***** 1 1 -1 -1 1 -1 -1 -1 -2Compared to Event 3 ***** ***** ***** -1 -1 -1 -1 -1 -1 -1 -7Compared to Event 4 ***** ***** ***** ***** -1 -1 -1 -1 -1 -1 -6Compared to Event 5 ***** ***** ***** ***** ***** 1 1 -1 1 -1 1Compared to Event 6 ***** ***** ***** ***** ***** ***** 1 -1 -1 -1 -2Compared to Event 7 ***** ***** ***** ***** ***** ***** ***** -1 -1 -1 -3Compared to Event 8 ***** ***** ***** ***** ***** ***** ***** ***** 1 -1Compared to Event 9 ***** ***** ***** ***** ***** ***** ***** ***** ***** -1 -1



I S I ≥ 15 I S I ≥ 20







-- -- -- -- -- -- -- -- -- -- SumCompared to Event 1 ***** -1 -1 -1 1 -1 -1 -1 -1 -1 -7Compared to Event 2 ***** ***** -1 1 1 -1 -1 -1 1 -1 -2Compared to Event 3 ***** ***** ***** 1 1 -1 -1 1 1 1 3Compared to Event 4 ***** ***** ***** ***** 1 -1 -1 -1 -1 -1 -4Compared to Event 5 ***** ***** ***** ***** ***** -1 -1 -1 -1 -1 -5Compared to Event 6 ***** ***** ***** ***** ***** ***** 0 1 1 1 3Compared to Event 7 ***** ***** ***** ***** ***** ***** ***** 1 1 1 3Compared to Event 8 ***** ***** ***** ***** ***** ***** ***** ***** 1 1 2Compared to Event 9 ***** ***** ***** ***** ***** ***** ***** ***** ***** -1 -1



I S I ≥ 15 I S I ≥ 20





Site-- ChillumCompound-- BenzeneWell-- GP-2E(45-50)


-- -- -- -- -- -- -- -- -- -- SumCompared to Event 1 ***** -1 -1 -1 -1 -1 -1 -1 -1 -1 -9Compared to Event 2 ***** ***** -1 -1 -1 -1 -1 -1 -1 -1 -8Compared to Event 3 ***** ***** ***** 1 -1 -1 -1 -1 -1 -1 -5Compared to Event 4 ***** ***** ***** ***** -1 -1 -1 -1 -1 -1 -6Compared to Event 5 ***** ***** ***** ***** ***** -1 -1 -1 -1 -1 -5Compared to Event 6 ***** ***** ***** ***** ***** ***** -1 -1 -1 -1 -4Compared to Event 7 ***** ***** ***** ***** ***** ***** ***** -1 -1 -1 -3Compared to Event 8 ***** ***** ***** ***** ***** ***** ***** ***** 0 0Compared to Event 9 ***** ***** ***** ***** ***** ***** ***** ***** ***** 0



I S I ≥ 15 I S I ≥ 20


EAST CENTERLINE - GP-2E(45-50) - BENZENE



Site-- ChillumCompound-- MTBEWell-- GP-2E(45-50)


-- -- -- -- -- -- -- -- -- -- SumCompared to Event 1 ***** -1 -1 -1 -1 -1 -1 -1 -1 -1 -9Compared to Event 2 ***** ***** -1 -1 -1 -1 -1 -1 -1 -1 -8Compared to Event 3 ***** ***** ***** 1 1 1 -1 -1 -1 1 1Compared to Event 4 ***** ***** ***** ***** -1 1 -1 -1 -1 1 -2Compared to Event 5 ***** ***** ***** ***** ***** 1 -1 -1 -1 1 -1Compared to Event 6 ***** ***** ***** ***** ***** ***** -1 -1 -1 -1 -4Compared to Event 7 ***** ***** ***** ***** ***** ***** ***** 1 1 1 3Compared to Event 8 ***** ***** ***** ***** ***** ***** ***** ***** -1 1Compared to Event 9 ***** ***** ***** ***** ***** ***** ***** ***** ***** 1 1



I S I ≥ 15 I S I ≥ 20

Result Decreasing Trend Result No Trend

EAST CENTERLINE - GP-2E(45-50) - MTBE





-- -- -- -- -- -- -- -- -- -- SumCompared to Event 1 ***** -1 -1 1 -1 -1 -1 -1 -1 -1 -7Compared to Event 2 ***** ***** 1 1 1 1 1 1 1 1 8Compared to Event 3 ***** ***** ***** 1 -1 -1 -1 -1 1 -1 -3Compared to Event 4 ***** ***** ***** ***** -1 -1 -1 -1 -1 -1 -6Compared to Event 5 ***** ***** ***** ***** ***** 1 -1 -1 1 -1 -1Compared to Event 6 ***** ***** ***** ***** ***** ***** -1 -1 1 -1 -2Compared to Event 7 ***** ***** ***** ***** ***** ***** ***** 1 1 -1 1Compared to Event 8 ***** ***** ***** ***** ***** ***** ***** ***** 1 -1Compared to Event 9 ***** ***** ***** ***** ***** ***** ***** ***** ***** -1 -1



I S I ≥ 15 I S I ≥ 20


EAST CENTERLINE - MW-25B - BENZENE





-- -- -- -- -- -- -- -- -- -- SumCompared to Event 1 ***** -1 -1 1 -1 -1 -1 -1 -1 -1 -7Compared to Event 2 ***** ***** 1 1 -1 1 -1 -1 1 -1 0Compared to Event 3 ***** ***** ***** 1 -1 1 -1 -1 -1 -1 -3Compared to Event 4 ***** ***** ***** ***** -1 -1 -1 -1 -1 -1 -6Compared to Event 5 ***** ***** ***** ***** ***** 1 -1 -1 1 -1 -1Compared to Event 6 ***** ***** ***** ***** ***** ***** -1 -1 -1 -1 -4Compared to Event 7 ***** ***** ***** ***** ***** ***** ***** 1 1 -1 1Compared to Event 8 ***** ***** ***** ***** ***** ***** ***** ***** 1 -1Compared to Event 9 ***** ***** ***** ***** ***** ***** ***** ***** ***** -1 -1



I S I ≥ 15 I S I ≥ 20


EAST CENTERLINE - MW-25B - MTBE





-- -- -- -- -- -- -- -- -- -- SumCompared to Event 1 ***** 1 1 1 1 -1 -1 -1 -1 -1 -1Compared to Event 2 ***** ***** 1 1 1 -1 -1 -1 -1 -1 -2Compared to Event 3 ***** ***** ***** -1 1 -1 -1 -1 -1 -1 -5Compared to Event 4 ***** ***** ***** ***** 1 -1 -1 -1 -1 -1 -4Compared to Event 5 ***** ***** ***** ***** ***** -1 -1 -1 -1 -1 -5Compared to Event 6 ***** ***** ***** ***** ***** ***** -1 -1 -1 -1 -4Compared to Event 7 ***** ***** ***** ***** ***** ***** ***** 1 -1 -1 -1Compared to Event 8 ***** ***** ***** ***** ***** ***** ***** ***** -1 -1 -2Compared to Event 9 ***** ***** ***** ***** ***** ***** ***** ***** ***** -1 -1



I S I ≥ 15 I S I ≥ 20


EAST CENTERLINE - MW-27B - BENZENE





-- -- -- -- -- -- -- -- -- -- SumCompared to Event 1 ***** -1 -1 -1 1 -1 -1 -1 -1 -1 -7Compared to Event 2 ***** ***** 1 -1 1 -1 -1 -1 -1 -1 -4Compared to Event 3 ***** ***** ***** -1 1 -1 -1 -1 -1 -1 -5Compared to Event 4 ***** ***** ***** ***** 1 -1 -1 -1 -1 -1 -4Compared to Event 5 ***** ***** ***** ***** ***** -1 -1 -1 -1 -1 -5Compared to Event 6 ***** ***** ***** ***** ***** ***** -1 -1 -1 -1 -4Compared to Event 7 ***** ***** ***** ***** ***** ***** ***** 0 0 -1 -1Compared to Event 8 ***** ***** ***** ***** ***** ***** ***** ***** 0 -1 -1Compared to Event 9 ***** ***** ***** ***** ***** ***** ***** ***** ***** -1 -1



I S I ≥ 15 I S I ≥ 20


EAST CENTERLINE - MW-27B - MTBE





-- -- -- -- -- -- -- -- -- -- SumCompared to Event 1 ***** 0 1 1 1 1 1 1 1 1 8Compared to Event 2 ***** ***** 1 1 1 1 1 1 1 1 8Compared to Event 3 ***** ***** ***** 1 1 1 1 1 1 1 7Compared to Event 4 ***** ***** ***** ***** -1 1 -1 -1 -1 -1 -4Compared to Event 5 ***** ***** ***** ***** ***** 1 1 1 -1 -1 1Compared to Event 6 ***** ***** ***** ***** ***** ***** -1 -1 -1 -1 -4Compared to Event 7 ***** ***** ***** ***** ***** ***** ***** 1 -1 -1 -1Compared to Event 8 ***** ***** ***** ***** ***** ***** ***** ***** -1 -1 -2Compared to Event 9 ***** ***** ***** ***** ***** ***** ***** ***** ***** 1 1



I S I ≥ 15 I S I ≥ 20







-- -- -- -- -- -- -- -- -- -- SumCompared to Event 1 ***** -1 1 1 1 1 1 1 1 1 7Compared to Event 2 ***** ***** 1 1 1 1 1 1 1 1 8Compared to Event 3 ***** ***** ***** 1 1 1 1 1 1 1 7Compared to Event 4 ***** ***** ***** ***** -1 1 -1 -1 -1 -1 -4Compared to Event 5 ***** ***** ***** ***** ***** 1 1 1 1 1 5Compared to Event 6 ***** ***** ***** ***** ***** ***** -1 -1 -1 -1 -4Compared to Event 7 ***** ***** ***** ***** ***** ***** ***** 0 -1 1Compared to Event 8 ***** ***** ***** ***** ***** ***** ***** ***** -1 1 0Compared to Event 9 ***** ***** ***** ***** ***** ***** ***** ***** ***** 1 1



I S I ≥ 15 I S I ≥ 20

Result Increasing Trend Result Increasing Trend




Site-- SmallvilleCompound-- Benzene

Well-- MW-12

Input data from four to ten sampling events in Row 10.

Event 1 Event 2 Event 3 Event 4 Event 5 Event 6 Event 7 Event 8 Event 9 Event 10 EventsConcentration 3,780 1,810 2,630 2,800 2,600 2,000 1,800 130 1,500 140 10

-- -- -- -- -- -- -- -- -- -- SumCompared to Event 1 ***** -1 -1 -1 -1 -1 -1 -1 -1 -1 -9Compared to Event 2 ***** ***** 1 1 1 1 -1 -1 -1 -1Compared to Event 3 ***** ***** ***** 1 -1 -1 -1 -1 -1 -1 -5Compared to Event 4 ***** ***** ***** ***** -1 -1 -1 -1 -1 -1 -6Compared to Event 5 ***** ***** ***** ***** ***** -1 -1 -1 -1 -1 -5Compared to Event 6 ***** ***** ***** ***** ***** ***** -1 -1 -1 -1 -4Compared to Event 7 ***** ***** ***** ***** ***** ***** ***** -1 -1 -1 -3Compared to Event 8 ***** ***** ***** ***** ***** ***** ***** ***** 1 1 2Compared to Event 9 ***** ***** ***** ***** ***** ***** ***** ***** ***** -1 -1




I S I ≥ 15 I S I ≥ 20


semi-annual progress report

Documents